My Life Depends on Tiny Bits of Rubber

A picture of my regular, a Scubapro MK2

So, I went on an Equipment Servicing course yesterday at the dive shop. As is the way of these things, it was held on one of the most sunny days of the year, but we couldn't have known that when we booked it!

Actually, it was worth giving up four hours in the sun for. I spend a lot of time with my dive gear, and it's good to know how it works. Also, taking things to bits is fun, although slightly alarming. The tiny bits of rubber in question are two pieces of rubber, each half the size of a penny, which sit inside the regulator (the thing you breathe through) and form part of the valves within it. In other words, they ensure that the air comes through only when you want it to, and not when you don't.

Some people on the course found this a bit alarming, although this may have been induced by the fact we'd all been sniffing glue. (The sort kept in the workshop to stick ripped-up wetsuits back together - it's not a very big workshop.) I can relate (to the alarm, not the glue sniffing - my poison of choice is ethanol). At 35m deep, sometimes, it's better to think along the lines of "It works by magic, la la la, DIVE FAIRIES", than to know exactly how tiny and delicate the mechanism currently keeping you alive is. On the other hand, my gear is serviced by the same chap who ran the course, and he has clearly forgotten more about how dive gear works that I will ever know.

So, I can now take my scuba mask apart and wash it, which has hopefully got the mould off it. Tonight, I shall learn if I can put it back together again. 

Done This For Real Four Times...

So, I spent a weekend refreshing my knowledge of Emergency First Response, or First Aid as we more usually call it over here. Nothing I hadn't done before, but you do need to practice, or you lose your skills. After a day and a half spent pounding the chest of a dummy and faking collapsing (I can do a really good convincing faint - practice makes perfect), I now have a shiny card. Much of the EFR course is spent teaching the following principles:

1. Thou Shalt Not Endanger Thyself
2. Thou Shalt Call The Ambulance
3. Thou Shalt Not Make The Patient Worse Whilst Awaiting The Arrival Of People With Actual Medical Training and Drugs

As is oft the way with divers, we could have treated it with more solemnity. Probably the most solemn comment was from my friend T, who used to be a mental health nurse, and commented that he'd done CPR for real four times "and they all died". Realistically, if your heart has stopped, the odds you'll be coming back are about one in ten. Still, the point is to try, and make sarcastic comments, as follows:

"He's hit his head, so he'll need to go to hospital so they can shine a light in his eyes and check his brain's still in there."

"There will be no flashing of boobs."

"Mate, the way you're coughing... I'm not giving you mouth to mouth!"

A Tour Around the Hat

So, the decompression dive! A fun day out, which began by trying on the Siebe-Gorman deep-sea commercial diving gear. This is the big brass helmet that everyone pictures when you say "deep sea diving", and was used by the Royal Navy until around 1980. There is a excellent reason they don't use it any more; it's incredibly heavy. The whole deep-sea rig, including weighed boots and ballast, weighs around two and a half stone more than I do. (For comparison, my usual scuba gear weighs about a third what I do.)

Commercial diving helmets are known as "hats", and it was quite fascinating being given a tour around the equipment, until the time came to get into it. I'm sure regular commercial gear is also pretty heavy, but with this you basically put it on and go in the water, just to get the weight off your shoulders. It was fun, and I'm glad I did it, but my dive log entry reads "Give me scuba any day!" At the end of the dive, the instructors gave us instructions for the decompression "dive"; interrupt the instructor a lot, and take a balloon in. (A balloon blown up at the "deepest" point of a chamber dive will explode as the pressure decreases on the way back up again, making a bang and getting bits of rubber all over the inside of the camber.)

Onwards to the decompression chamber. I don't know what you may be picturing, but try picturing a big metal cyclinder on legs in someone's basement, and you've pretty much got it. (Surrounded, for some reasons, by pictures of pin-up girls. Apparently Scubapro used to think "naked tits" were what they needed to use to sell dive gear back in the day; thank God we've moved on - a bit.) The chamber looks so small, you cannot imagine one person fitting in, but five of us managed to sit next to each other.

A "chamber dive" involves sitting in a decompression chamber whilst the air pressure inside is increased to the equivalent of a 50m deep dive in water (beyond the recreational limit). This allows you to experience the narcosis you get at this level; nitrogen breathed under increased pressure makes you feel drunk. The chamber attendent then decreases the air pressure, including two decompression "stops" on the way "up", and at some point, the balloon goes bang. This is a useful experience to have for two reasons; 1) it gives you the experience of the narcosis you get when diving to 50m, and the sensation of being unable to "surface" (or leave the chamber) until the dive concludes, and 2) you get to experience what chamber treatment is like, which is good since it's the standard treatment for decompression injuries sustained when diving.

I was expecting to be nervous, but the dive was, actually, very good fun. Probably it's the narcosis, but we had a whale of a time. Except for the attendent, who spoke through the chamber's radio in tones of deep resignation "Can you pick up all the pieces of the balloon on the way out, please."

"I've Done This For Real..."

I've been busying myself arranging some dive training. I shall be spending tomorrow at the Diving College near York, playing around with old-fashioned dive gear, and doing a "pot dive", where they put you in a hyperbaric chamber and drop the pressure to the equivalent of a 50m dive, which is beyond my current range. I'm a bit nervous about this last one, but it will be good to find out what a "pot" is like on the inside, since if I ever have an accident whilst diving, that's where I'll end up.

Hyperbaric chambers are known as "pots" by divers, after one of the most famous; the chamber designed by Jack Haldane, son of JS Haldane who, among his many other accomplishments, pretty much single-handedly created dive tables and made it possible to dive without giving yourself the bends. More about the amazing Haldanes here: Grace under pressure.

The next  training course will be in two week's time, and will involve no diving at all; I'm renewing my Emergency First Responder certification. Basically a First Aid course angled at divers. I last did this two years ago, and I'm overdue a refresher. My memories of the last time I did this mostly go as follows:

• One of the senior divers there had a small white Scottie dog that used to live in the shop. One look at all of us crowding in to do our training, and it ran and hid under the wetsuit rack, and wouldn't come out. 
• Most First Aid training is less about splinting broken bones and more about "here's how to keep them alive until the ambulance gets here".
• The instructor [who works as a nurse] started the CPR training by remarking "I've done this for real three times; they all died". (Statistically, that's pretty much how it goes. the odds are one in ten, but you do it in the hope that the person you're currently rescue-snogging will be the one in ten.)

The next stop is to refresh my Rescue Diver training. It is one of my weirder accomplishments that I can give people mouth-to-mouth in the sea.  Here's hoping I never have to.

In One Way, Depth is Just a Number...

(I started writing this post back in 2010, came across it, and decided to revive it. As of 2013, I'm a Rescue diver, albeit I do need to go back to Lake Ellerton and practice fishing people out of the water some time soon. Funny how even back then I was picking holes in PADI's teaching methods...). 

And in others, it isn't.

As part of my Advanced Open Water Certificate, I'll be doing a "deep dive" whilst in Bute for the diving weekend I'm going on in March. For those not familiar with recreational diving limits, I currently have an Open Water certificate, which means I'm qualified to dive as deep as 18 metres.

In common with (I suspect) most Open Water divers, I have somewhat bent this rule - without getting myself bent, I hasten to add - whilst diving in the tropics. My deepest dive so far was 23 metres in the Maldives to see an interesting sunken ship. It was at the start of the dive, myself and my buddy had full tanks, I wasn't tired or dehydrated and I kept a close eye on my dive computer and air gauge, so I figured I wasn't running an unacceptably high risk of burning through my breathing gas or running out of bottom time. I was right.

A quick digression on some terms I'm using here:

Bent = getting the bends; decompression sickness causing by ascending too fast or staying down so long you can't come straight up but have to do decompression stops. Recreational or sports divers, like me and like everyone when they first start diving, do the sort of dives which don't require decompression stops, so that at any point in the dive, you can abort it and ascend to the surface, albeit at a slow enough rate that you don't get the bends. This is for safety reasons.

Bottom time = the amount of time you can stay submerged before you have to ascend. Governed by two factors; how much breathing gas you have, and how much nitrogen you have absorbed from breathing gas under pressure. The amount of nitrogen you have absorbed governs how long you can stay under without needing to do decompression stops to allow the nitrogen to leave your system so that you don't get the bends. The two factors are interlinked: If you're at a deeper dive, you go through your breathing gas faster, because it is delivered at a higher pressure. This also means you're breathing in more nitrogen molecules - it's a compressed gas, so there are more gas molecules in each breath you take in - so you absorb more nitrogen and have a shorter period of time you can safely stay under. Also one of many diving terms that causes juvenile humour to occur. 

For my "deep dive", I'll be going deeper than this. It's surprisingly hard to find out exactly how deep online - it's something I'll ask my instructor - but probably around 25-30 metres deep depending on the conditions.

This post starts "In one way" because a novice diver saying "depth is just a number" and leaving it at that implies that person hasn't fully grasped that deeper dives do come with a set of distinct challenges. These include the aforementioned shorter bottom time periods and the fact that they use gas a lot faster than shallower dives. They also include the unique aspect of getting the narcs.

The narcs = nitrogen narcosis. Essentially, the deeper you go, the more the higher concentration of nitrogen you're breathing makes you feel intoxicated. It's most commonly compared to being drunk, although symptoms vary from diver to diver. The narcs are harmless in themselves and go away if you ascend (safely) to a higher depth. The risk comes from feeling a bit drunk 30m below the water. It's even worse for technical divers, who have to fiddle around with their gases to try to come up with a mix that won't send them completely off their heads whilst 60m down.

But in one way, I believe that depth is just a number. Why? To me, it's in the mind. One thing I think PADI's Open Water Diver course does run the risk of is encouraging newbie divers to think "It's okay if things go wrong, I can always go back up again". I think that's the wrong mindset. Sure, there are times when a CESA (controlled emergency swimming ascent - swimming up to the surface if you've run out of air, but keeping your weight belt on so that you don't rocket up there, and exhaling to stop you from getting lung overexpansion injuries) or even the dreaded buoyant ascent are the right, i.e. only, options to handle the situation.

Buoyant ascent = ditching your weights so that you immediately become positively buoyant and fly up to the surface in an uncontrolled ascent. Extremely dangerous as you run the risk of getting lung overexpansion and the bends. Absolute last-ditch measure for getting to the top if all other hope is lost. Comes with a big AVOID DOING THIS IF YOU POSSIBLY CAN in the diving training manuals.

However, I think that's a risky mindset. It encourages you to think that all problems are solvable and there's always a way out, whereas you should be thinking about how to prevent the problems in the first place. You can get the bends coming up from 12m or even shallower. Going deeper increases the risks, but the risk is always there.

Dive safely, folks. And remember... in British waters, there's frequently bugger-all to see at 30m in March in the Farne Islands. 15m is more fun, and there are seals!

Assertiveness for Divers, Part 3: Your Buddy is Not a Telepath

And the final section of this little essay, and one of the trickiest things I've had to learn as a diver: assertiveness with your buddy.

By this, I don't mean aggressiveness, or in-your-faceness. I don't mean a situation where you're telling your buddy "We have to do it my way!" Unless they're proposing something completely hare-brained, like diving to 40m on a 10l cylinder, playing with Great White Sharks, diving in caves with one torch with elderly batteries, in which case, have at it and / or, find another buddy.

For me, it's always been a more of a subtle thing. It's easy not to rock the boat, particularly if it's your regular buddy. After you've done it a few times, a buddy check can seem a bit superfluous. And you know which route you're following round the site - after all, you've dived it umpteen times before. And you're pretty sure you've both got the same goal for the dive. And you don't want to sound too much like a newbie diver who does everything the PADI manual way...

...except that, without the buddy check, you might not realise that your buddy has recently started wearing integrated weights, not a belt. Or that they've bought a new BCD with different releases. Or that one of you wants to stop and take pictures with the new camera. And when you get into the water, it turns out that the visibility is a lot poorer than you expected. And your buddy still wants to take photos, and the next thing you know when you pause to look round, they're not there and you can't see them.

I could keep going in this vein, but I think the point is coming across. Admittedly, everyone dives differently. I wouldn't try telling more experienced divers than I am what to do with their buddies. I do know, however, that it took me a while to get this point in my head, and to have the courage to risk looking like I'm overly-cautious, or that I do it too much by the book, and ask my buddies to do a proper buddy check with me. I'll also ask everyone I'm diving with to confirm the plan for the dive, anything they want to watch out for on the dive, what the plan is if we get split up, and where the car keys are. (By which I really mean "If it all goes tits-up and we have to drag you back to land, what's the quickest way to get to the mobile phone and call the ambulance?").

As for under the water... I say this goes double. Maybe it's me, but I find it can be tricky to communicate with other divers at the best of times, which is why I now carry a slate and pencil at all times. Sign language is great when it's all going well, but throw in some more vis or an unexpected problem, and trying to get the point across can be tricky. I came across this on a dive to Malta (remember that?) when my BCD shoulder valve leaked on the first dive of the holiday, and dumped all the air out of the jacket, and thus out of my cylinder.

I think there's a temptation under the water to not want to have to hold up the dive, to stop and say "Actually, I think there's a problem". This is not helped by the fact that some divers like to take off like rockets into the distance. I'll admit this is a pet peeve of mine; I really wish more divers in groups would actually stop and look around to check everyone is okay and keeping up, rather than leaving it to anyone having a problem to signal this. There can be a real temptation, when the dive leader signals "Ok?" to reply "Ok!" instead of "Problem over here!" and just think, "hey, it'll sort itself out".

I fell prey to this. I did, eventually, manage to signal my buddy that I had problems, but that was twenty minutes into the Dive of the Leaking Jacket (albeit it took me ten minutes to figure out what was happening). The first time around, I tried writing on the slate "Jacket leaking?" My buddy checked and wrote "Looks fine!" (Of course it did, I later realised - it had leaked all the air out, and thus wasn't visibly bubbling - I should have filled it with air whilst she was looking!)

It took me another five minutes to pluck up the nerve to go back to my much-more experienced buddy and try again to say "Actually, this dive really isn't working for me". This time around, I figured the solution, and showed her my air gauge, which showed I'd used about twice the air I normally would on a dive at this depth for this duration. This got the point across, she swam off to notify the dive leader, and he and I headed off at 3m to return to dry land and repair the valve.

And again, I learned a valuable lesson. Don't misunderstand me. I would never abandon my buddy or leave them to struggle, and I know they would do the same for me. But when it comes down to it, you are going to go play in an environment where, as Captain Bob Bates memorably paraphrased it, "where a single breath of the ambient atmosphere will, kind reader, fucking kill you" (Snappy Banter website.) 

The more I dive, the more I firmly believe that if you are not prepared and able to complete the dive using your own resources, if you are relying on your buddy to get you through it then, unless it's a teaching environment when your buddy is the instructor and is there to keep an eye on you, you are in a really dangerous situation. To quote another scuba website, "It's a buddy, not a crutch". You don't need to be prepared to do the dive if it all goes right. You need to be prepared to handle the dive if it goes wrong. If something happens to your buddy (leaking regulator, cutting themselves badly on some sharp wreckage, severe cramp meaning they can't swim), then you are going to have to be prepared to take charge of the dive and get the two of you safely back to terra firma.

I love diving. I also love driving my car. In both cases, I keep my skills in tune, my equipment maintained and an eye on the prevailing conditions. And because I do that, I've returned safely from every drive and every dive I've had (so far). And I find that when you include the risks in your dive plan, you can head out feeling more secure than if you ignore them, because you know what to do.

Happy diving, folks.

Assertiveness for Divers, Part 2 - Self-Assertiveness

I was originally going to write this as "Assertiveness with your buddy", followed by "Assertiveness with yourself", but found that didn't work, as the one in many ways precludes the other.

In sense, what I'm writing about is not assertiveness at all, but honesty with yourself. Perhaps self-assessment is a better term than self-assertiveness?

I suppose what I am getting at is this. I don't know whether what I'm about to describe is true for all divers; the answer is "probably not all, but some". I feel there's a tendency among newer divers to fail to take full responsibility for their safety when diving, and if this continues as a habit it can be a real danger.

The reason for this is pretty simple. When you learn to dive, you are learning to do an entirely unnatural activity in an environment that can kill you. This is not unlike learning to drive, and both activities involve a very early stage where you have little idea what the hell you are doing, you don't know what all this equipment does, and you must have absolute faith in your instructor. With diving, even more so than with driving; your instructor literally has your life in their hands. They know far more than you do, and in the interests of learning to do it safely, you must suspend relying on your knowledge, place your trust in them and let them guide you.

The main difference between the two activities is that when you pass your driving test, you will shortly afterwards find that you are in a car, on your own, with no-one there to hit the brakes for you if you bugger it up. This is the point at which you realise they make the driving test so bloody hard so that when you find yourself in this situation, your skill level will be high enough that you should be able to get yourself out of the inevitable mistakes you'll make without killing yourself or any bystanders.

With diving, however, you continue to dive with someone else, due to the buddy system. And, due to your own lack of experience, this person is more experienced than you. It can be very, very tempting to rely on them to do a lot of the hard work of planning a dive - choosing the location, timing and date, checking the tide and weather conditions, planning the route and, not least, planning what to do if it all goes horribly wrong.

In the early stages, this is pretty inevitable. It takes quite a few dives to really get the hang of managing yourself and all your gear in the water, much as it takes quite a lot of driving experience after you pass your test before you master it to the extent that you can drive the car without thinking about it. However, there comes a point where you must start to take responsibility for yourself.

Why? Simple. Because you only get one life.

I had this knocked into me when I overbreathed my regulator at 22m in the Farne Islands, with my two buddies out of sight in front. The sensation of being unable to get enough air to breathe properly with 22m of water overhead is uniquely horrible. It scared the hell out of me, and to this day it's why I'm not sure I'll ever try technical (decompression) diving. I made it back safely then by resisting the urge to hit the inflator button and rocket to the surface by repeating to myself "You are getting enough air to survive the few minutes it will take you to rise at a safe speed to the surface, and once you're up there this horrible feeling will go". The thought of having a near-panic attack with twice the water over my head and no possibility of a direct ascent to the surface scares me rigid just sitting at my desk writing this.

And from this experience, I took away a useful lesson: you have one life, which you take down there with you, and if you don't manage your dive properly, you are the person who will feel the consequences. Not your buddy. I don't blame my buddies for what happened. I should have realised that I was overexerting myself and slowed down to stop the situation before it started. But when that happened, it was me who felt like I was suffocating, me who nearly panicked, and me who, if I had panicked, would quite possibly have ended up in a hyperbaric chamber with a nasty case of the bends (or worse). Not them.

This is not me having a go at the buddy system, which I think is an essential part of recreational diving. It's me saying that I don't always know if every diver really takes on board the fact that if there's any aspect of the dive you personally didn't plan or think about, you're putting your life in the hands of the person who you trusted to do that - and, if they didn't do that, that's your safety at an unnecessary risk.

So be assertive with yourself. Ask yourself if you really know what the dive involves, what equipment and skills it requires, and whether you can handle it if it all goes wrong. If not, think twice about doing it. Because, again, you only get one life.

Assertiveness for Divers, 1

This post was inspired by this article: "4 Reasons Divers Die". I've been a follower of this series of articles ever since I started diving (and it must be said that the opening paragraph of that article sums up most of them). When it comes to diving, I take the view that whilst it's great to learn from your mistakes, when it comes to breathing pressurised gas 30m between the ocean surface, it's even better to learn from someone else's mistakes.

Douglas, like his predecessor at SCUBA magazine, Michael Ange, lists four main reasons divers die:

• Poor health
• Procedural errors aka not keeping in practice and failing to remember what your Open Water instructor taught you about dropping your weights / recovering your reg / making a safe ascent, etc.
• Environmental factors aka not being prepared for the conditions, linked to failing to evaluate the conditions. If you learned in the Red Sea, regardless of how many dives you did, it may be wise to try your first dive in the UK in a quarry or off a sheltered shoreline, rather than jumping off the boat at the Farne Islands into water of around 10 degrees C, wearing twice the gear you are used to, into waters that feature currents bearing nicknames such as "Fastest Route to Norway". (I hasten to add, the Farnes are safe to dive even for relatively new divers - so long as you're used to the cold, the visibility, and the fact that when the boat driver says "Don't go round the headland", he means it.)
• Equipment failures aka failure to actually maintain your equipment. Well-maintained open-circuit scuba gear very rarely fails; fail to maintain it, and either your regs or your BCD will let you know all about this.

If I'm allowed to, I'd like to add one more key preventative measure to the list above (keep your health up, practise your skills, be realistic about the conditions and your ability to dive them, and keep your gear well-maintained). Assertiveness.

I really think PADI should teach this on the Open Water course, although I can understand why they don't. New scuba students are often nervous enough without something else to add to the list.

But in the real world, when your instructor is not there to watch over you, assertiveness is key. I can think of three ways to apply this:

1. Assertiveness with the dive operator
2. Assertiveness with your buddy
3. Assertiveness with yourself

1. Assertiveness with the dive operator

You will need this when you dive abroad. You will need it when you walk into a dive operator you have never been to before, in a country you have not dived in before, and especially if you are going to do boat dives, where the boat picking you up is probably going to be your only route home.
You will need this (or at least I do) to enable you to push beyond taking the operator's glossy photos or website at face value and ask them: does the boat have oxygen? What sort of dives do they do, and how many guides are there on them? What level of skill are they suitable for? When you're on the boat, where's the liferaft and the lifejackets?

Handy hint; if they don't ask to see your logbook, or ask when you last dived, this is a sign that you should go dive with someone else - if they're that sloppy about the divers they're taking out, how careful are they with the equipment?

You may need assertiveness not to care if you encounter huffiness, or incredulity that you're asking these questions - many people don't. And you need to be prepared if you end up having the following conversation at the start of the dive:

[dive briefing ends] Divemaster: "Any questions?"
Me: "Where is the oxygen on the boat?"
[lengthy pause]
Divemaster: "Were you diving yesterday? Do you feel you may have decompression sickness?"
Me (out loud): "No, I just thought I'd ask."
Me (in head): "No, and I bloody hope I don't get it whilst I'm on your boat."

Oxygen is the number 1 treatment for decompression illness (catch-all term for gas embolism or getting the bends or both, essentially the most serious consequences you can have from diving and potentially fatal). This guy was taking a boat of ten divers in choppy seas out for a 30-minute ride to do a 25m dive to a sunken Messerschmitt in the Mediterranean, which is not in the same risk category as technical diving, but with a bottom time of only 20 minutes, qualifies as "deep diving" where it would be relatively easy to overstay your bottom time and increase your risk of DCI.

Pop quiz: If there's no oxygen on the boat, you get a DCI hit, and the total time to get you back to the nearest oxygen cylinder, assuming it's waiting on the quayside for you, is:

time taken for boat crew to realise you have a problem and haul you back onboard
+
time taken to recall everyone to the boat and get them back on it, one-by-one
+
time taken to get boat back to shore

How long is it going to be before you can get the treatment that could save you from permanent paralysis, or worse?

I'm going to go with "around an hour". Fun, huh?


Incidentally, on the second dive of the day, the case with the oxygen cylinder and mask was sitting rather pointedly on the main deck of the boat. Kind of amusing, since that guy also tried to tell us it was under one of the seats on the boat. (We checked. It was not.) A wee bit late.

More follows.

Malta Day 1 – Accidents and Emergencies, Part the Fourth

 And indeed the Tugboat Rozi is a splendid wreck, one I’d really recommend to anyone. It’s mostly intact and has lots of fish, plus the cabin is open for that inevitable “diver sitting on a toilet underwater” photo that everyone likes to take. At one point my buddy spotted a barracuda in the distance. Best of all, I handled the depth, staying mostly relaxed and happy. I felt a little strange at one point, stopped, gently rose a metre or two, and it went away. Eventually, inevitably, our computers began to count down the minutes until we started to reach the ‘five minutes til you go into deco(1)’ moment. 

And this is where things went a wee bit wrong.

Firstly, the current. As we headed back towards our planned exit point, we encountered a strong current which kept pushing us back towards the ship. For most of us, this was an annoyance but not a serious problem; we dropped down slightly to get out of the worst of the current. (Currents tend to be strongest the nearer you get to the surface of the water.) 

Unfortunately, this was not an option for two of our number, who were running low on air and for whom dropping longer would have meant risking running too low. They stayed shallower to conserve air, and found themselves being pushed further and further backwards. My buddy, a Divemaster, noticed this, and slowed down to watch to see if they were okay. The rest of the group, alas, didn’t notice this and kept going. I did my best to keep my eyes on both the struggling two divers, my buddy, and the rest of the group, but eventually reached the point where the group had simply vanished into the blue.

The two running-low-on-air divers eventually appeared to decide to surface, and myself and my buddy tried to decide what to do next. We followed our compasses in the direction the group had taken, and eventually found ourselves near the exit point next to the lighthouse. (Again, props to the excellent maps in the "A Guide to Shore Diving the Maltese Islands" book by Peter Lemon – I saw several metal beams in the water near some rocks, and instantly recognised them from the drawing in the book as the wreckage which indicates you have found the exit.)

We looked up to see the waves crashing overhead. 6m down, the water wasn’t moving too much, but it was clearly a different story on the surface. We’d have to go around the rocky outcrop to the planned exit point at Suzie’s Pool, which, being more sheltered, would be much calmer.

I checked my air (a bit low but not dire), my computer (which was doing a safety stop for me), and my buddy. And then realised what my buddy was staring at…

(1) ‘Going into deco’ is divers’ shorthand for staying down either long enough or deep enough (or both) that you have to do a decompression stop. In other words, you have stayed under long enough that your body has absorbed so much nitrogen (from the compressed air divers breathe) that you cannot ascend directly to the surface without an unacceptable risk of getting the bends.

This is when the nitrogen dissolved in your body tissues “bubbles out” destructively on ascent, due to the decreased pressure as you ascend to shallower depths. “Bubbling out” happens on all dives, but if you have too large an amount of nitrogen in your tissues and / or you ascend too quickly, the bubbles are so large that instead of being safely transported through the bloodstream into the lungs and exhaled, they become trapped and damage your tissues and circulatory system.

When this has happened, you must do a decompression stop, where you ascend to a certain depth and stay there until you’ve exhaled sufficient of the nitrogen stuck in your system that you can ascend further without an unacceptable risk of getting the bends. This is a regular part of technical diving. Technical divers, however, carry extra gas and an entirely separate scuba breathing system with them, so that in the event of one of their sets of breathing gas failing, they can switch to the other and still safely carry out decompression. The extra gas is also calcuated to last for the length of the dive plus decompression stops and a safety margin. Finally, they carry diving computers which can calculate decompression stops based on the divers’ time and depth during the dive. 

Recreational divers, of which I am one, do not carry this amount of gear as it’s not needed for dives without decompression stops. (The extra gear for technical diving is expensive, heavy, needs much more maintenance, and you have to do a lot of training and learn extra skills before you can safely dive with it. Each diver makes their own choice about whether the extra time and expense is worth it for what they want to achieve when they dive.) This means that, should you have to do a decompression and you have problems with your breathing gear or run low on gas, you face the choice every diver plans to avoid: run out of gas or get the bends. Neither is desirable.

Malta Day 1 – Accidents and Emergencies

Recently I spent eight days in Malta, courtesy of my friendly local dive shop, with ten fellow divers. We explored the island and drank much beer.

I'd like to point out that any bugger-ups recounted here are entirely my own fault. No blame attaches to anyone else! So, onward...

The Diving Holiday in Malta team’s first day was spent at Marfa Point, aka Cirkewwa. About an hour’s drive from St Peter’s Bay, it’s where the Gozo ferry leaves from, and also has several excellent dives in its own right. We had our trusty guide to Malta’s diving, penned by Peter Lemon, whom we bumped into in the Dive Shop later in the week. (I’m not being sponsored by him or anything, but if you want a guide to diving in Malta, buy his. It has excellent directions, including compass bearings, good descriptions, and undersea maps that actually make sense when you get under the water.)

Should have been a doddle of a check-out dive, following by an interesting dive on the wreck of the Tugboat Rozi, right? 

Well…

Our first dive was to be around the area known as “Suzie’s Pool”, an area often used for training dives, and thus a logical place to have our first “check-out” dive of the holiday. Always a good idea to test out everyone’s skills and equipment before the more challenging dives. In my case, it was going to be particularly useful, since I had with me my old BCD, which I now use for travelling. The new one is more up-to-date, comfortable and ergonomic, fits over my drysuit, has integrated weight pockets – and also weighs a ton, so it no longer comes with me on holiday unless I have extra baggage allowance. I’d had the old BCD serviced back in February, hadn’t used it since June, and had meant to have a pool dive with it the week before we left, but life got in the way.

I kitted up with 6kg of lead, figuring that since I was wearing the 5mm full-length suit of my two-piece semidry suit – but not the jacket, hood, neoprene socks, 5mm gloves or rash vest that complete the rest of my diving ensemble back in the UK – I could knock 3kg off what I needed. I’d been diving on 6kg in Crete earlier in the year with the same set-up. 

We slithered into Suzie’s Pool, in some cases literally as the sea was vigorously splashing onto the rocks* and swam out to the drop-off. Or in my case, didn’t, as I seemed to be pinned onto the rocks. I signalled my buddy and wrote on the slate I always carry with me: “Too much weight.” 

Looking back, this should have been a clue. Even if 6kg was a little on the heavy side taking into account the amount of neoprene I’d lost from my usual diving set-up, I’ve dived with that BCD on 9kg of lead and a lot more gear, and it can produce roughly 20kg-worth of lift. Even if I was over-weighted, it should have been possible to compensate by adding a bit more air to the jacket.

Still, buddy and the nearby dive leader fiddled about with my weight belt and removed a weight, always an interesting experience when all your weight is on your belt. Fortunately, with only 3 minutes’ dive time and 4m of water above my head, even a buoyant ascent would probably not have done me too much damage. Even more fortunately, this didn’t happen: the dive leader tucked the weight into his BCD pocket, and we set off into the blue.

And then things got worse. 


To be continued…


* Yes. This will become an important detail later on on this blog.

Things I Learned From My Last Dive (St Mary's Island)

Note: Lest it be thought otherwise, these are my own thoughts on what I learned from my last dive. It's not intended as a criticism of my dive buddies. I take the view that I'm personally responsible for my own dives and if something went wrong, I need to think about what I personally could have done differently to prevent it.

1. Never abdicate looking up the tides and currents to someone else, even if they’re a Divemaster and your internet connection isn’t working.  YOU'RE responsible for your safety, not them.
2. The handsignals for “You two stay together and wait here, I’ll go up and take a compass bearing” look disturbingly like the handsignals for “You two buddy up, I’m ascending and ending my dive”.  
3. If you don’t understand the message someone is conveying, don’t let them do anything until you do. Write it on the slate if you have to.  
4. In poor vis, agree with your buddies in advance that the dive moves at the pace of the slowest diver, and that the people leading will look back frequently to check that there are still the right number of people present.  
5. In poor vis, get close on descent, and hold hands (or a buddy line) on ascent to avoid getting split up. 
6. Never let the guy with the broken compass lead the dive. 
7. Always carry audio and visual signalling equipment. 
8. Spend time keeping your fitness up. My buddy and I had to surface swim for about 20 mins with a tide running. Every minute I’ve ever spent in the gym on the treadmill was worth it, because an unfit diver would have been struggling, and trying for a tow against a current is a difficult thing. 
9. On the North Sea coast, heading West will pretty much always get you back to the coast.

On the plus side, I faced my fear of overbreathing my reg at depth, and overcame it. We all got back in one piece. And as we surfaced, and I thought “Bugger me, that lighthouse is a long way off”, I saw the Red Arrows performing in the distance for the Great North Run, and the inspiration powered us back to the lighthouse, and a very welcome biscuit.

Vertical Ships, Idiot Bartenders, and McBob (Oban Diving) – Digression

And we rose early in the morning, and hopped into J’s Jaguar to head on down to Oban Harbour, and load all of our gear onto our floating base for the day, the Peregrine. This is one way in which diving in Britain differs from diving overseas, at least in my experience. Just about all types of diving involve early starts, but diving in Britain usually involves hauling a lot more heavy gear about, due to a) absence of paid friendly divemasters to do it for you, and b) diving in Britain requires a lot more stuff. It’s no wonder I’ve started lifting heavier weights at the gym. 

Interestingly enough, I recently realised that perhaps part of the reason why of all the hobbies I’ve tried – martial arts and archery included – diving is the one that’s stuck; it plays to my physical strengths. Partly, it’s just that I love the water. I literally cannot remember a time I couldn’t swim, as I was first taken to a swimming pool by my dad before I was one year old – my conscious memory doesn’t get back far enough! 

Curiously enough, you don’t actually have to be a great swimmer to be a diver*, although it certainly helps. Most divers don’t need to master anything other than the basic flutter kick, which is the same one used in front crawl, and the fins do the rest. (It’s different for techie divers, who need to have very precise fin strokes to avoid stirring up silt in caves and wrecks.) You do, however, need to be confident being in water, and swimming certainly helps. Bobbing around in the middle of the North Sea in three-foot waves waiting for the boat to find you and pick you up really isn’t the right time to be at all nervous about being in deep water. 

Getting back to my point, the one thing I physically lack is speed. I can run. I just can’t run fast. This is affectionally known in my family as the “Curse of the CylingDiverClan”**. None of us have any acceleration, although quite a few of us have done half-marathons and fun runs. Alas, nearly all school sports require the ability to run really fast, and hence my school sports career was best described as undistinguished. I can, however, hit my stride and stay in it for some time. 

Since diving requires you to actively avoid doing things fast – it wastes energy and leads to inefficient breathing – but does require continous exertion over a period of around 40 minutes, it’s perfect for me. My fondness for lifting large lumps of metal helps out too. Being able to squat-thrust 30kg in the gym is great preparation for standing up with 13kg of lead strapped around you, and a 12litre tank of steel and compressed air on your back adding another 15kg to play with. 

Standing up with all of that on you on a boat is an interesting experience, and one I was about to have. More details on that, and the afore-mentioned McBob, next week!


* This is one of the Big Three questions I get asked when people learn I go diving. The other two, which nearly always follow when people learn I go diving in Britain, are:

“Don’t you get cold?” Polite answer: “No, not if you’re wearing the right type of suit to go diving in.” Honest answer: “Would you enjoy being cold for half an hour? Do you think I’d enjoy being cold for half an hour every weekend when I could be doing something else? Ergo, do you think I get cold?”

“Can you see anything?” Polite answer: “Yes, it’s possible to see quite a lot. We can get up to 10m visibility, and there are lots of starfish, crabs, fish and anemones to look at, plus the seals and the wrecked ships.” Honest answer: “No, I love spending half an hour swimming around in the murk looking at nothing.” Though, to be fair, that’s a good description of one or two dives I’ve had at Beadnell Bay, and don’t get me started on Lake Ellerton.


I know, I’m irritable. I used to get deeply irritated when I did martial arts and people would say to me, on learning that this was my hobby: “Ooh, I won’t disagree with you then!” I used to want to reply: “What, you seriously think I’m so violent I’d hit you if you disagreed with me?” I guess one of the great lessons of life I’ve had to learn in the past thirty-odd years is People Like To Make Obvious Comments, and nobody ever, ever, thinks if you might have heard the same thing before and be fed up with answering it.



** No, that is not our real surname. Though it would be pretty awesome if it were.

The Wonderful World of Drysuits

Well, I finally took the plunge. (Sorry.) I have bought myself a drysuit. For those who know nothing about what that is, it’s a watertight fabric suit with built-in boots and rubber seals at the neck and wrists to keep water out. You wear it whilst diving, with a warm undergarment underneath it, and it keeps you a lot warmer than a wetsuit or semidry suit - air is a less efficient conductor of heat, and thus a much better insulator than water. 

Given that cold has been a limiting factor on most of my dives, you might wonder why I’ve never bought one before. Answer: they’re expensive. The drysuit itself, plus its undersuit, hose to attach it to the air tank (the suit is inflated at depth from the scuba tank, to stop it being compressed by the increased water pressure), and the training course to teach me to use it safely, cost £500. Had I bought it from a slightly less nice dive shop, i.e. one that didn’t chuck in the hose and undersuit along with the drysuit, it would have been more. 

Alas, this was but the start of my expenditure. My semidry fins are too small to fit the bigger drysuit boots, so it was off to Deep Blue Dive to buy a pair two sizes bigger, and thus spend another £99 plus £2 for a beeswax stick to grease the drysuit zip and stop it sticking. 

And finally, my old buoyancy jacket is too small to fit properly over the drysuit, so it’s a new BCD for me, at the cost of £360. Yes, it has occurred to me that I could have gone on a week’s holiday for the amount I’ve just spent on dive gear. 

On the other hand, it was more than worth it to be able to do two dives in the Farne Islands, including the sitting about on the boat afterwards, and not be cold at all. I had not realised how much of my energy was being taken up on my dives by managing my responses to the cold. I saw far more on the dives than I usually do, simply because I’m not continually trying to win the mental battle against the cold. Much safer and much, much more fun. Never again will I feel my dives cut short by the cold. 

Also, the new BCD is fantastic. I’m not on commission, but it’s an Oceanic Hera, specially designed for women, and the joy of a BCD which fits properly and doesn’t make me feel like I’m being hugged by a boa constrictor when I inflate it fully. It has integrated weights*, and for a few moments on the boat, as I loaded in my integrated weight pockets and zipped up the drysuit, I felt like a proper diver. 

Until I realised that the reason the regulator wouldn’t screw onto the top of the scuba tank is because I’d forgotten to take the tank valve cap off. Oops.


* weight pockets inside the buoyancy jacket. Preferable to the old-fashioned system of wearing all your weight on your weight belt, as it distributes the weight across your body. It also means that if you have to dump weight, you have the option not to ditch all your weights, an action known as “doing a Polaris ascent”, since ditching all your weights tends to result in sudden positive buoyancy and rocketing up to the surface, probably giving yourself the bends or an arterial gas embolism (every bit as nasty as it sounds) on the way. Instead, you can ditch either your weight belt or your weight pockets, giving a bit more control over the ascent.

Boat of Puking Divers, Part the Fourth

The other best cure for seasickness is to jump in the sea. Since it’s caused by confusion between the signals for the eye and the inner ear balance mechanism, being in the sea, and thus moving with it, cures this. Hence the oft-recommended cure for seasick divers – “Just go on the next dive” – is not born entirely of heartlessness. (Although there may be an element of that among the more gung-ho instructors.) And yes, you can throw up through a scuba regulator mouthpiece underwater, though I imagine it’s not much fun.

The first batch of divers kitted up for the second dive, and jumped in. Two of them promptly jumped back out again; a diver from Edinburgh whose drysuit was leaking badly, and A, who threw up at the bottom and promptly decided he didn’t fancy half an hour’s swimming around and puking through a reg (since the cause in this case was an OD on brandy, jumping into the sea didn’t cure him).

L decided that he would take A’s place on the dive, and jumped in, leaving me with J as my dive buddy. As I kitted up, I wondered balefully if this was L’s idea of revenge over the failure-to-stop-vanishing-banana incident.

We submerged as fast as was safe. In answer to a frequently asked question, yes, you can (and we do) dive when it’s raining, but it’s not ideal for two reasons, even though we are planning to submerge ourselves entirely in water: a) rain and wind stir up the sea and lower the visibility, and the lack of light means photos don’t come out so well, b) it’s one thing to be entirely surrounded by water, and another to be bobbing about on the surface getting cold water repeatedly blown into your face. Think of the difference between swimming in the pool and getting caught in a winter downpour without an umbrella. It’s like that.

This dive immediately looked more promising. The vis was not brilliant as we were relatively near the shore, so the surge (waves going back and forth overhead) was pushing a bit of sand around, but the light was a bit better and there was immediately more to see. More plants, more fish, more rocks, and less depth, so more light to see them. Also, a welcome absence of the slightly sick feeling I’d had in the pit of my stomach. It was so mild I hadn’t realised I had it, until I submerged and it went away. (It may not surprise anyone that it was whilst diving off Eyemouth that I developed my habit of singing “I Feel Better” by Hot Chip to cheer myself up during surface intervals.)

We happily paddled about hunting for lumpsuckers. It was an interesting experience, which I’m tempting to say was a bit like diving in a washing machine, albeit the sea didn’t actually spin us around! I don’t particularly mind diving in a bit of surge or current, as it’s quite fun playing with the sea. (Albeit a wise diver never ever forgets that the sea is bigger than you are, stronger than you are, doesn’t get tired, and has no affection for you whatsoever.)

Suddenly, J spotted it. There, beneath a rock, was a flash of pink in the sandy water. I promptly swam on over, and was rewarded with a sight I’d never seen before: a lumpsucker guarding its eggs. As you can see from the photo, the “lump” part of the name is apt. They must be one of the least hydrodynamic creatures in the sea.

As for the “sucker” part, the lumpsucker has an interesting reproductive cycle. They normally inhabit deeper waters than most divers venture into, but during spring, the lumpsuckers migrate into the shallower and warmer waters near the shore to lay and fertilise their eggs.

The female lumpsucker then thinks to herself “bugger this child-rearing lark, I’m off”, and swims back into the deeper waters, leaving the male lumpsucker to guard the eggs, which are attached to rocks near the shoreline. The male then attachs himself to a rock near the eggs to defend them and keep them oxygenated by finning water over them. Since the eggs are on rocks near the shore, the swell of the tide going in and out would dislodge the male, were it not for the part that his ventral fins (the fins just below the head) form a sucker, which he uses to firmly anchor himself.

I was extremely excited by this sighting. I enjoy the sensation of diving in itself, but for me an extra-good dive is when I see something I haven’t seen before. The photo I took can be seen above. We paddled around the rocks some more, then headed on back to the boat for the journey home and a hot chocolate. Several toasted sarnies in the harbour café afterwards, and we were on our way home from the Boat of Puking Divers.

Boat of Puking Divers, Part the Third

B sat with his arms folded.

“Why aren’t you going back in?” I asked, as I attempted to make myself a coffee whilst not acquiring a burn on my left arm to match the one on my right (the result of an accident with a kettle earlier this year); no easy feat when the boat is pitching around.

“It’s cold.”

This surprised me, as B is by no means a fair-weather diver. Then it occurred to me. “Didn’t you just get back from the Phillipines?”

He gave me a look of deepest gloom. If you imagine the expression of people who have just arrived back on the plane from Florida in August wearing t-shirts, shorts and sandals only to look out of the plane window and see black skies and hurling rain, multiplied by a factor of ten, you’ve more or less got it. “Yup.”

“’Scuse me.”

This was not B, but A, another regular dive buddy of mine. A suddenly stood up and dashed past me to join the other divers on the puking side of the boat*. This also surprised me, since I’ve never seen A throwing up on the boat.

“What’s up with him?”

“Two bottles of wine and a brandy last night.”

“No sympathy then.”

“’Scuse me.”

B pushed past me to join A. This was becoming a pattern. I looked through the wildly-lurching porthole, and counted five people throwing up over the side. This was something of a record, which J, the senior divemaster pointed out with slightly more relish than was necessary. I decided to go outside myself; I’m not usually cursed with seasickness (thank you, God), but even I was feeling slightly “off”. The best way to cure this is to sit in the fresh air and look at the horizon, which I did for all of five minutes, before I got fed up with being rained on and decided I could look at the horizon through the entrance to the cabin.

As I wandered in vaguely thinking about a Mini Roll, J was asking “Does this banana belong to anyone?”

I looked across. “Yes, it’s L’s,” I replied, somewhat pointlessly since half the banana was well on its way to become part of J. I sincerely hoped this meant L wasn’t going to be suffering on our next dive. I can’t say that I was exactly looking forward to the dive – I was having visions of the warm seas, clear water, and sunshine I hoped to encounter on my upcoming summer holiday in Crete** – but it did have the great advantage that it would take us away from the boat of puking divers.



* There is a system for this, and it’s mentioned in the PADI Manual, believe it or not. You go to the leeward side of the boat (leeward = if you stand on that side facing towards the sea, the wind is blowing on the back of your head, not the front – windward is the other way around), and throw up over the side, the theory being that the wind will blow it away from both you and the boat. Which makes sense, since if there’s one thing guaranteed to add insult to injury when you’ve just thrown up, it’s getting it all blown back in your face. (The PADI Manual also helpfully adds: “Stay out of the head [toilet] – that’s about the worst place to go”).

** Correctly, as it turned out. Watch this space.

Boat of Puking Divers, Part the Second

I cannot say that the first dive out of Eyemouth was the most visually interesting dive I’ve ever done, but in its own way, it had a certain hypnotic calm. Vis was not too bad, and we were at 12-15m. The only real sights were the pale grey rippled sand beneath us, the green water around us, an occasional rock or crab on the bottom, and thousands of small hydroids in the water around us. Hydroids are the free-floating larvae of sea anemones before they attach themselves to rocks, and look like very small jellyfish. It was a surreal experience, but in some ways almost meditative, drifting steadily along with the current and following the divers ahead.

After half an hour, I was mentally taking bets with myself as to how soon it would be before the large male novice diver (LMND) in front of me got towards the reserve on his air tank and we went up*. I interspersed this with the occasional barrel roll to see if my buddy was there, as he had a fondness for swimming about two metres above me. Technically I should have been swimming at the same level he was, but I like to see what’s on the bottom… he told me afterwards that drifting along with the current with only the bottom for reference was giving him nausea and vertigo, and he was happier swimming a bit higher up.

The answer proved to be “not that much longer”. LMND and his buddy started to head upwards, accompanied by a flurry of hand signals from the instructor in charge of the dive. My buddy produced his SMB and deployed it at about 6m whilst we were making a safety stop: it was as well he did it at this depth, as the line attached to the damn thing got tangled around his tank valve, and we did the underwater Untangling Waltz. Buddy and I surfaced with no mishaps and yoicked ourselves back onto the boat (thank god for boats with lifts).

The instructor informed us that his hand signals had been intended to mean “you two can carry on if you want to”. We replied that our actions had been intended to mean “we know, but we don’t want to ‘cause it’s a bit cold and boring, and we fancy a cup of tea and a Mini Roll”.

In search of the aforementioned Mini Roll, I lurched into the cabin – the sea was getting quite choppy – and encountered a shivering, coat-wrapped and be-hatted mass in the form of one of my regular dive buddies, B. B looked up at me and ground out “I’m not going back in there”.

It was going to be one of those mornings.


* Risk factors for going through your air quickly: being a physically large person, being male, and being new (new divers tend to move through the water less efficiently, and waste more air through inflating and deflating their buoyancy jackets). The reserve air is the amount of air everyone on the dive agrees to have left at the end of the dive, usually around 50 bag. You never plan to dive until the tank is empty, for safety reasons – you need the reserve in case something delays you on the way to the surface or one of your buddies runs low on air.

Deep Dive at Stoney Cove

Last week I fufilled a long-standing ambition to dive with my aunt M, the only diver in the family until I took it up, and her buddy S. S is a technical diver, extremely knowledgeable - the sort of person who services her own regulators*.

We dove at Stoney Cove, one of the two major inland quarry diving sites in the UK (Capernwray is the other one). It was my first freshwater dive, all my dives to date having been in the sea, meaning that on the first day there we did a short "check dive" so I could get my weights right. You are less buoyant in freshwater than in salt water, so you need less weight to offset the exposure suit's buoyancy. I normally dive with 9kg in salt water, and dove with 5kg in fresh, using the same exposure suit but a slightly larger tank: 15L compared to my usual 12L for floating around Beadnell.

Stoney Cove was fun. There were a lot of fish - roach and perch - down there, and quite a few crayfish. I recorded my deepest ever dive, 32 metres. We followed the old quarry road down to the deepest part of the pit. Didn't quite get down to the bottom, as M signalled that she was getting a little cold. I wasn't too bad so long as we kept moving, but it was cold down there; about 7 degrees C. I remember thinking "Hey, look at all those big numbers on my dive computer!" followed shortly by "Hmm, 6 minutes of no-decompression time left... that's not so good, time to turn this around". That was about when M signalled she was cold, so we didn't make it as deep as the Deep Hydrobox, which lies at 36m in the quarry. Next time!

Perhaps I should have been more scared than I was, diving that deep, but I don't remember being scared. Once you get past about 15m, you can't rely on CESA-ing your way out of trouble, and I've dived deeper than that before. At that depth, you rely on your training, your dive plan (and gas planning), and close communication with your buddies. I didn't feel narc'ed, though we didn't do any tests for it - perhaps my slower reaction to seeing the 6 minutes on my computer was a sign? I felt in control, though, so it's difficult to tell.

More tales coming soon.

* The things you breathe through.

"I Had Air Coming Out Of My Eyes" (Boat Dive)

Is not a sentence, thankfully, that one hears very often.

Let me backtrack a little.

I did my first boat dive in the UK last Sunday, off Eyemouth, just over the Scottish Border. It was the first club boat dive in the UK for the season*. Our Chief Instructor introduced the first dive with words along the lines of "this is the first boat dive of the season, let's be careful whilst everyone gets used to doing this again and be prepared for things to go wrong".

He was right.

It's fair to say that I'm at that stage of experience (22 dives as of last Sunday) where, despite my shiny new card saying "Advanced Open Water", I still begin each dive wondering what I will manage to do wrong this time. I'm not a particularly awful diver (I like to think), but diving is complex enough that until everything becomes second nature, there's usually so many things going on at once that I manage to get one of them wrong. Fortunately, my training was good enough that it's usually the smaller things like "forget to put fins on before scuba unit**" on the boat rather than the really important stuff like "check all the connections are in place, the air valve is turned on and the jacket is inflated BEFORE going in the water".

It's easier to put your fins on first on a boat, since it's more difficult to bend down and tighten them with the scuba unit on your back. On a shore dive, the fins only go on once you're about to go in the water, since it's nearly impossible to walk over rocks wearing fins. One of many things I learned last Sunday.

I really enjoyed the dives, but the same cannot be said of us all. Our tally of mishaps included:

a) A diver in the first group surfacing a minute or so after the group had started to descend with the memorable words that form the title of this post, preceded by "I can't equalise". Being unable to equalise your ears and sinuses*** is a situation all divers dread, as it makes diving impossible and means you've had a wasted trip. It's usually caused, as it was here, by having recently had a cold and having blocked sinuses, making it impossible to push air up the sinuses and equalise the pressure on the inside of the ear drum. He had tried repeatedly to do this, apparently so hard that the air had leaked out of his eyes via the tear ducts. I had not previously known this was possible.

b) One diver with a flooded mask and regulator knocked out of her mouth at the same time. An awful situation to be in, since you lose your ability to breathe and to see at the same time. We do, however, train for this; regulator recovery and mask clearing are among the first skills every diver learns before you are passed fit to dive. Doing them in training is very different to doing them unexpectedly in a real situation, and I was most impressed by how calmly she told us this afterwards. (Didn't want to go back in again afterwards though - I'm not sure I would have wanted to either.)

c) One diver with severe seasickness. Apparently the cure for this on a dive boat is to have them jump back in the sea and swim about - it's not too cold to do this if you're wearing a full 7mm semidry suit with hood, boots and gloves. I didn't know this, either, but unfortunately it failed to work. If you try this, you have to avoid it coinciding with another diver deciding to use the "other head". The "head" on a boat is the toilet to landlubbers, and the "other head" is "off the back of the boat", if you happen to be male. Getting an eyeful of pee, or even just an eyeful of peeing diver, isn't going to do anything for the sickness.

d) Two divers deciding after the first dive that one was enough for the day. It was a very cold first dive, and any diver can decide to stop diving for any reason - not feeling happy on the dive is all the reason you need.

e) One diver with a snapped fin. He must have caught it stepping off the back of the boat into the sea. It split nearly in half, hanging on by the barest thread. I was swimming behind him on the dive, and spent at least ten minutes thinking "is it going to snap, will we be towing him back to the boat, is it going to snap now, will we be towing him..." etc.


Other than that, it was a good trip - for me, anyway. I hadn't done a boat dive in the UK, and part of the reason for my wanting my shiny new Advanced Open Water card was to be allowed on the boat - the skipper of the boat we were diving from insists that all divers must be AOW to be allowed on. One difference between it and the Maldives was that this boat had a boat lift, essentially a small platform that descends from the back of the boat far enough into the sea for a diver in the water to stand on. The platform then rises so that you don't have to climb back onto the boat - it lifts you up. Neat! And very practical. I was fine climbing out of the boat in the Maldives, but trying to do so in a full 7mm semidry suit with 8 kilos of weight round your waist at the end of a dive would be a different kettle of fish.

I got two dives in. I have to say that the first one wasn't awful, but I wouldn't quite class it as fun. I was a bit nervous on the descent, mainly because as I descended further I realised my weight belt was a bit too loose - I must have failed to cinch it tight enough on the boat. This was not a good situation. Aside from making it harder to swim, having your weight belt come off is risky. Losing 8 kilos of weight is a sudden enough buoyancy change that you would risk an unplanned buoyant ascent, which can give you DCI****.

I considered trying to tighten the belt, and decided to leave well alone, reasoning that although the belt wasn't tight enough, the buckle itself was firmly fastened, and the belt wasn't loose enough to slip over my hips when I stood up on the boat or when I was swimming. I weighed up "slightly loose weight belt which is staying on" versus "possibility of losing it altogether if I undo the fastening" and decided to leave well alone.

Probably I should have gone for the third option, "ask buddy for help". That I didn't is no reflection on him, but rather a reflection on my own feeling that I wouldn't have been able to signal clearly enough what I wanted him to do, and also signal the other divers in the group to slow down and stay with us. I made it to the end of the dive with the weight belt firmly in place, and learned a valuable lesson about the importance of donning the belt properly. Second dive = no problems with belt!

As a consequence of this and of the fact that during the descent I couldn't seem to find the inflator hose for my buoyancy jacket (it sits on my left shoulder, and I'd probably have been able to find it easily if I hadn't been so distracted), I was sucking air pretty fast. When we got down there, I remember thinking "I am breathing WAY too fast, calm down, calm down, breathe slow". I calmed down, breathed slow, and followed everyone else along a most impressive reef dive. Not much fish life, but many anemones and sea urchins, very striking to look at. We swam through fields of kelp and hung on to it to keep ourselves stable during a safety stop***** (another trick I learned last Sunday).

Most of that first dive was uneventful, but cold. It was 15m deep, which is plenty deep enough in British waters in April without a drysuit. I am seriously beginning to hear the call of the drysuit. I hate to be cold more than anything else, and whilst on a dive I can usually put my feelings about being cold "in a box" and focus on something else, after about half an hour the dive ceases being fun. Unfortunately, the dry suit plus the undergarments plus the training to use it safely costs a pretty penny or two, so I'll be diving wet for a while. Not that the manufacturers of my semidry suit fell down on the job; when I peeled it off for a quick pee, my body was sufficiently warm that water vapour was rising off me. It's just that everyone's tolerance for cold differs. Ah well, one of these days...

I settled myself inside the boat, bundled myself in a jacket, drank some coffee and ate a chocolate mini roll. Ah, the joy of diving; the perfect excuse to eat whatever you like... Shortly afterwards I headed back out again to get some fresh air. Sitting inside the cabin was like being in a small box being violently shaken by a giant, and I was not feeling so great. Some fresh air, and I was fine.

As ever, I had to nerve myself a bit to go back in for the second dive - the little voice in my head was going "You want to go BACK in there where it's all cold?" - but I had paid my money, and wanted to dive.

I'll admit, there was a stupid pride thing going on too. I was going to be the only female diving with the second group, and, if I'm really honest, part of me wanted to show that I can do two dives, just like the men. Which is a stupid reason to dive, I know. Nobody on that boat is sexist, or would seriously question that... it's all in my head, I know. But, more importantly, I really, really, wanted to dive.

The second dive was shallower (second dives always are) and over "the boilers". These are bits of a wrecked ship, which have been down there so long they don't resemble a ship, but you can see which bit used to be the boiler. I got back in there, and the second dive went much better. No problems with weight belt, no problems with buoyancy hose, ears equalised just fine, buoyancy control was nice and smooth. Only thing I got wrong was ascending a little too fast at the end (my computer beeped at me), but I don't seem to have suffered any damage as a result.

It was a good dive, nice visibility, lots of interesting wreckage to look at and I think I saw a fish. Most of all, there was the joy of being underwater in a pack of divers. When diving goes well, when your ears are clear and you hover weightless in the water with neutral buoyancy, powerful fins propelling you easily through the water, swimming in a team with your fellow divers... there really is no feeling like it. I'm trying to describe it, but my words really aren't doing it justice.

It was a good day. Accidents, seasickness and air coming out of tear ducts notwithstanding.

* The UK diving season runs roughly in line with British Summer Time i.e. around April-October. It's not to do with the clocks going back or forwards, just that this is roughly when the water is warm enough and the weather good enough to make diving feasible for the majority of recreational divers. It's certainly possible to dive in colder conditions, but this generally requires more gear and a generally higher level of complexity. For the majority of recreational divers wanting to dive in the UK, April-October is the main "dive season".

** scuba unit: the inflatable buoyant jacket, air tank ("bottle") and regulators to breathe through. The bottle is strapped onto the jacket, the regulator's valve screws on the top of the bottle, the jacket's air hose is connected to the bottle with the low-pressure inflator connection, and you put the whole thing on like a sleeveless jacket.

*** equalising your ears; as a diver descends, the increased water pressure puts the ear drum under strain due to the lower pressure on the other side of the ear drum, just like when you descend in an aeroplane whilst flying. The solution is the same, too; you pinch your nose, then blow against it gently to push more air into the sinuses and air passages within the ear, thus equalising the pressure on both sides of the ear drum and reliving any discomfort. Simple to do, but absolutely vital. If not done in time, you can damage your ears badly.

**** DCI = Decompression Illness. Term referring to someone showing symptoms that could be caused by either the bends, a lung overexpansion injury (where you have come up too fast and the air in your lungs has expanded at a rate that has damaged them - ascending at a safe rate avoids this) or, if you're really unlucky, both. Decompression sickness (DCS) refers specifically to the bends.

***** Three-minute stop at five metres' depth. Recreational divers plan their dives to avoid having to do decompression stops, for reasons I'll rabbit on about in a later post. We do, however, do safety stops, which are not mandatory (unless you've been diving deeper than about 30 metres - even then, you still theoretically shouldn't need them, but you would do them to avoid risking the bends), but considered advisable to minimise any risk of getting the bends. Especially prudent on a cold dive where divers work harder and consequentially breathe a larger volume of air, thus loading more dissolved nitrogen into your body tissues.

Why You Don't Want Your Lungs To Be Like A Bursting Balloon.

And another post on diving, following on from the last one.

So why might your lungs be like a bursting balloon?

The answer to this is the answer to the question about why the absolute cardinal rule of diving is "Don't ever hold your breath". This might seem like a statement of the obvious, breathing being somewhat important to life. However, there is another reason, not obvious unless you know how scuba gear works.

As stated earlier, the regulator which divers breathe through is a device for delivering breathing gas* at ambient pressure. Thus, if the diver is at 20m deep, they will be breathing air at three atmospheres of pressure (one atmosphere of gas - the Earth's atmosphere - plus 20 m of water = three atmospheres of pressure).

Now, supposing the diver begins to ascend? Obviously, as she moves into shallower water, the pressure on the outside of her ribcage decreases (less deep water = less water pressing down on you). If she is holding her breath, the air on the inside of the ribcage, however, in her lungs, will be at the higher pressure the regulator delivered it at, at the deeper depth, so that she could expand her ribcage to breathe.

It does not take a qualification in physics to work out that this is a bad situation. The higher pressure gas will start to expand inside the lungs. The possible consequences can be seen in this video about Boyle's Law:

If the gas expands too much, part of the lung will rupture, letting air into the bloodstream - arterial gas embolism. Anyone who has ever heard a radiator pipe banging because it has air in will grasp why getting gas bubbles in your bloodstream has potentially fatal consquences for your internal organs.

So why, if there is this potential risk, do thousands of people dive every weekend as routinely as if they were playing a game of Sunday morning football? Because it's an easy injury to avoid. Hence the advice: "Don't ever hold your breath!". If you keep continously breathing from the regulator, the gas inside your lungs is always at the same pressure as the water (or air if you're on the surface) surrounding you.

This is also partly why divers are trained to ascend slowly - it ensures that your breathing keeps pace with the pressure changes during ascent, minimising the risk of lung expansion injuries. (The other reason is to do with not getting the bends, another topic for a later post.)

And thus, the problem can be avoided.

* There's a reason I'm not calling it "air", that's for a future post.

Why Your Ribcage Is Like A Car Door In An Action Movie

A post about diving, this one. I haven't posted on diving for a while, mainly because I haven't been doing any. I intend to do a refresher session in Fenham pool first thing next month, and after that I hope to be back in the sea very soon.

Usual disclaimer: I'm not a trained diving instructor, I'm posting this because I like to talk about diving, DO NOT rely on stuff I post here for your safety whilst diving.

So why is your ribcage like a car door in an action movie? This relates back to a much earlier post where I commented that the foundation stone of diving knowledge is that gas compresses under increased pressure, and expands under decreased pressure. To build on this, we need to know that when Cousteau and Gagnan developed the "aqualung", what they developed was a way to deliver breathing gas on demand to the diver from a portable tank on the diver's back at ambient pressure. In other words, the gas the diver breathes in is at precisely the same pressure as the air (if on the surface) or water (if submerged) surrounding her.

Why is this important? Going back to the car door. If you have ever seen an action movie where the hero and his girlfriend are trapped in a sinking car in the river, you will know that it is not possible (assuming the movie is obeying the laws of physics) for him to open the door until the water has flooded into the car. Why? Because the water on the other side of the door is pressing against the door with more pressure than the air on the inside of the door (water being heavier than air), holding it closed. Not until there are equal amounts of water on both sides of the door can he open the door and swim to safety.

So too with the human ribcage. To expand and contract, the pressure within the lungs must be equal to the pressure outside the ribcage. Normally, at sea level, we breathe air at one atmosphere (i.e. the air pressure is the pressure of the Earth's atmosphere pressing down on us). To submerge beneath the sea, we must breathe air at the same pressure as the pressure of the weight of the water pressing against us. Otherwise, our lungs would simply collapse - only if you were Superman would you be able to expand your ribcage to get air into your lungs.

Water is much heavier than air. As anyone who has done their Open Water basic diving certificate knows, at ten metres deep, the water pressure is equivalent to two atmospheres of air. (10 metres of water. 122,000 metres of air. Mindbending.) Thus, the regulator delivers air at the equivalent of two atmospheres of pressure, meaning that the ribcage can expand and contract with the same ease it does at sea level.

Impressive stuff, is it not?

Now, watch this space for my next post on this topic: Why You Don't Want Your Lungs To Be Like A Bursting Balloon.