Scuba Diver's Log

17 May 2010. Wraysbury Dive Centre, Middlesex.

First dive was for 15 minutes, achieving a depth of 7.2m. Water temperature 12 degrees celcius.

Wore a hired 5mm full length BodyGlove suit and a 5mm shortie and carryied 12kg in weight. Hired from Ocean Turtle in Basingstoke, along with a hood, regs and buoyancy control device.

Entered water from ramp and followed instructor, Simon, into deeper water. Saw nothing except some pond grass, shingle and other divers. Visibility poor – around 3m.

Performed some mask clearing and regulator retrieval exercises at the end of the dive, in shallow water.

That’s it – the log of my first dive. Like aircraft pilots, divers meticulously record the number of hours they’ve spent going about their business. For pilots it’s flying time, for divers, dive time. You can buy specially prepared diving log books, complete with smiling and frowning faces to tick as a record of your overall impression of the dive.

Logging time is important because hours equate to experience. Recording other information is equally valuable because you’d soon forget exactly what equipment you were carrying and what issues you encountered. Writing a log soon after the dive creates a record you can refer back to and will probably come in useful in the future. When you return to a dive site you can use the log to remind yourself of potential problems or sights to look out for.

I haven’t bought a log book yet but I probably should. I’m certainly not logging every dive on this blog although I’m tempted to log it electronically, perhaps online using Google Docs, but that will make it less accessible offline. A physical log book is a useful paper record but it's something else to carry around and, in my case, something else to misplace.

If you have any novel tips for a diving log, or ideas for other things it's useful to record in it, why not leave a comment on this post?

Don't Panic - You're A Scuba Diver

When you’re under water it’s important to stay in control.

To complete the scuba diver training you need to keep a firm grip on your emotions. You’re in an unnatural environment, entirely dependent on your equipment to keep breathing, and sometimes fear threatens to get the better of you.

In one of my early pool dives I unexpectedly had an almost uncontrollable desire to breathe through my nose. This is impossible when you’re wearing a mask, and unnecessary because I was being fed air through the regulator in my mouth.

Nevertheless, the sudden urge to breathe through my nose was almost overwhelming and for a moment it seemed it would only be satisfied by a swift rise to the surface. I didn’t give in, telling myself it was ridiculous. After a few moments the mood passed and I was fine.

Panic is when you act in an uncontrolled and often irrational way, driven by fear. It can be triggered by tiny things, such as my need to breathe nasally or suddenly having your mask fill with cold water. Different sparks effect different people. Simply contemplating how much water is between you and the fresh air might be enough to tip you into a panicked trip to the surface.

I can only write from my own experience but I’d be surprised if other divers don’t have moments when they need to get a grip of themselves. In my first open water dive, last weekend, the visibility was poor and at one point I was descending into gathering darkness unable to see anything but my dive buddy.

Don’t worry, I told myself when I sensed the first pangs of anxiety. You’re in a relatively shallow training lake and there’s nothing between you and the surface. Don’t let irrational fears get the better of you.

I didn’t let the anxiety take root and I went on to enjoy the dive. I also meet the BSAC requirement to have dived in a low visibility environment. It doesn’t get much worse than that, my buddy and instructor informed me.

So diving is a test of character. Do you have what it takes to deal with irrational fears, a momentary lack of air or a mask filled with water? If you don’t, scuba diving probably isn’t for you. On the other hand, you might be suprised at how easy it is to cope with these challenges if you think through the scenario logically before you do it, and simply focus on achieving each step in order.

And at the end of the day, consider what's the worst that can happen? Even in a basic pool dive there are multiple layers of safety and as long as you're sensible, you're very unlikely to come to any harm.

Open Water

Wraysbury Dive Centre is a hole.

I mean literally: a man-made depression in the Earth's surface, a short distance west of Heathrow Airport and the M25 motorway that circles London.

Once one of many gravel pits that pock-mark the area, it's now full of water and, at the weekends, full of divers.

We visited Wraysbury Dive Centre on Sunday for our first open water excursion. That is, our first dive outside of a swimming pool and our initiation into the wider world of scuba diving in the UK. After weeks of being stared at by casual swimmers in the local pool and feeling slightly out of place, we were suddenly surrounded by divers - lots of them - squeezing into wetsuits and swinging air tanks onto their backs. "It's going to be diver soup", said Geoff, our instructor.

As a relatively shallow man-made lake near to London, Wraysbury is almost an ideal site for diver training. You have to try very hard to dip below 10 metres because in most places the water's simply not that deep. It's also relatively warm, for a lake, because it's so shallow. They've even sunk a few vehicles to add variety to the underwater landscape.

But it's also very silty and when filled with trainees struggling to control their buoyancy it doesn't take long for the water to cloud with muck kicked up by fins and crash-landings on the lake bed. The result is poor visibility (or 'vis' in diver-speak). At its best on Sunday you could see about 3-4 metres. At its worst you knew you'd come across a sunken taxi or bus because you literally swam into it.

One good thing about poor vis was it rendered the other divers in the water invisible. Judging by the numbers on the shore when we arrived there must have been plenty underwater by the time we dived, but once down we didn't encounter very many. What wasn't so good about the vis was trying to stay in touch with our instructors, who were liable to vanish from sight with just a couple of fin kicks. But they did a great job of looking after us novices.

One of them brought along a camera and snapped the picture of me at the top of this post.

I don't know if I'll go back to Wraysbury Dive Centre. It provided a great introduction to diving outside of a pool environment and the poor vis and crowded water created new challenges. One of the pleasures of diving, I'm told, is to encounter marine life in its natural habitat. The only living things we saw in the water on Sunday were neoprene-clad figures with masks and fins.

How I (Almost) Mastered Mask Clearing

A problem shared is a problem halved.

Don't you just hate irritating little sayings like that? Patronisingly pithy words of wisdom, wrapped sweetly and succinctly for delivery just when you don't want to hear them.

They're made all the more annoying by encapsulating a truth that you know even before you're reminded of it.

This time I decided to get ahead of the game and share my mask clearing frustrations. I blogged about them here and had one or two useful comments, but I also asked for advice on the UKDivers.com forum which I've recently joined.

The response to my posting on this scuba diving discussion site was immediate. I received lots of friendly feedback from divers who agreed that mask clearing was the one thing that almost everyone struggled with. Some shared tips from their own experience and many offered encouragement that I'd eventually conquer it. Practice and persistence were the key, apparently.

"It was the skill I most struggled with" wrote PuddleFish. "The least enjoyable part of my OW" (Open Water) said Major Clanger. "I too had a lot of problems with mask clearing" concurred Steppenwolf.

I immediately felt better about my inability to blow air through my nose to push the water out of my mask. The gasping, choking embarrassment was not my unique problem; I was facing a barrier that many others had encountered and eventually overcome.

In addition to this reassurance came advice. How about clearing the mask before putting on the strap, suggested Jenkins. "I also find it easier to clear the mask before putting the strap on", agreed Toria82.

Now there's a thought. I'd already been encouraged to practise breathing in through my mouth and out through my nose when diving, which worked fine. The exhaled air pushed its way out from under my mask and no water came in.

So when it came to the next mask clearing session I removed the mask completely and breathed out through my nose. I started to put the mask on, under the water, and exhaled through my nose as I did so. In a moment the mask was half-empty and I'd barely put it on my face.

I tilted my head back and exhaled again and the mask was cleared. I was then able to put the strap around my head and the job was done.

To prove this wasn't a lucky one-off I did it again, at my instructor's request. I was then asked to remove the mask once more, led on a circuit of the diving pool at 3m depth (with my eyes closed because the water stung) and then replaced the mask using the same technique. It worked!

With the help of my virtual dive buddies I seem to have got to grips with mask clearing. It wasn't as easy as I've made it sound, and this technique I've adopted only works when I remove the mask completely. I'm still not entirely happy clearing a mask that's half-full of water and strapped to my head, but I can do it without inhaling much water.

What this proved to me was that the problem could be overcome and, perhaps more importantly, that there's a great community of divers out there who are willing to help. I'll probably never meet Puddle Fish, Major Clanger or the others I've mentioned here, and I might never even learn their real names. But I appreciate their input into my diving education.

Thanks, guys!

BSAC versus PADI

Is it just a friendly rivalry?

I went to a dive shop today which offers training the PADI way. The owner, a Professional Association of Diving Instructor, asked me who I was training with and snorted distainfully when I said BSAC. He suggested that it wasn't too late to change, joining one of his courses.

When I first mentioned the possibility of diving to a friend, a few months ago, they immediately recommended that I train with BSAC. The British Sub Aqua Club training, they assured me, is for proper divers, not just the fair weather sort who'll only go into warm tropical waters.

Not surprisingly, they'd been BSAC trained themselves. I received the same advice from a member of Scot SAC, the Scottish Sub Aqua Club (who are different from the British version, apparently).

On their website PADI describe themselves as "the world's leading scuba diving training organisation", with over 135,000 professionals world-wide.

BSAC are "the UK's leading dive club and the sport's national governing body".

PADI have hundreds of training centres around the world, where you can sign up for a course. According to their website my local centre would charge me £299 for basic training, plus £100 if I wanted to do open water dives (that is, in a lake or the sea). The course fee includes supply of the necessary equipment.

BSAC, on the other hand, have lots of clubs around the UK, some of whom offer training. Their charges are much less, under £200, but they may not be able to supply all the gear you need for open water diving. My group supply everything that I need for training in the swimming pool but that's it.

PADI instructors make money from training people whereas BSAC don't - they're all volunteers and their charges simply cover costs, such as club membership and access to pools and open water for diving.

I'm sure that as I encounter more divers I'll discover more about this evident rivalry between BSAC and PADI. At the moment it feels as if PADI position themselves as the up-to-date professionals and regard BSAC as the well-meaning but slightly backward amateurs. From the other side of the pool, BSAC think of the themselves as the guardians of true diving and see PADI as focusing on deep dives into your wallet.

There is, I think, a healthy mutual respect between members of both organisations and they often dive together. At the end of the day, when you're under water you want the confidence that your dive buddy is going to look after you, regardless of whether they're BSAC or PADI trained.

The shop owner that I met today was definately pro-PADI and scorned much of the advice I'd received from my BSAC colleagues. But interestly, when he was out of earshot, his shop assistant, himself a regular under the water, confided that he envied BSAC because they did what he called "real diving".

Lesson Two

I don't really like water.

It's one thing to be downing a glass, putting it inside me, but I'm not so keen when I'm inside it. Particularly when I'm three metres down and being asked to take out my regulator (the thing I breathe through) and throw it to one side.

There are bits of this training that I'm not looking forward to. Jumping in was one, mask clearing is another. Then there's removing and clearing the regulator underwater, swimming without a mask, air-sharing, jumping into cold water, diving in zero visibility and... Actually, there's quite a lot that I'm not looking forward to!

It was a pleasant surprise to discover that removing and clearing the regulator wasn't as difficult as I'd feared. We practised on the surface, where I managed to swallow a mouthful of tasty chlorinated pool water. But three metres down, on the floor of the diving pool, it felt remarkably easy.

I took out the regulator, threw it casually to one side, then swung my arm to find it again and back in my mouth. A firm blow to push out the water and there I was, breathing again. I quite enjoyed the practice and even made a point of pausing for a few seconds between tossing it aside and trying to get hold of it again. Hey - I'm a scuba diver!

Mask clearing wasn't so pleasant and I can't claim to have mastered it. Divers wear masks that grasp their faces like limpets and which keep the water out. But we have to learn how to clear a mask in the unlikely event that water gets in.

I put my face under water, let some of the stuff trickle into my mask, then put my head back and tried to clear it. My nose stung as I inhaled chlorine filled water. I splutter and coughed and gave up. A second attempt was equally unsuccessful.

In hindsight I think I know where I went wrong. Divers learn to breath through their mouth because that's where you put the regulator. The nose is covered by the mask and becomes useless for breathing. But during mask clearing you blow out through the nose to push water out and the natural next step is to breathe in - through the nose.

I think that's where I went wrong and I'll test it out next week. Apparently I'll also be learning how to remove and replace the mask, including clearing it, when underwater. That sounds like fun.

So next on the tick list of challenges to overcome is mask clearing and handling the pressure in my ears. But I'm sure my instructors have plenty more in store for me!

Under Pressure

Have you ever lifted a bucket full of water?

Heavy, isn't it? Imagine what's required to lift a diving pool full of the stuff, or what it would feel like to lie underneath it.

Because that's exactly what happens when you dive. Gravity pushes the weight of the water downwards onto you. What's odd is that you're not aware of it. This is where it gets all scientific and beyond my limited comprehension - somehow the interplay of forces on your body prevents you from feeling the weight, or from being crushed by it.

At least, it seems that way. In fact the air inside your body does get squashed as you dive, and you don't need to go very deep before you feel the effects. If you've ever dived into a pool and swum down to about three metres (or ten feet) you'll probably have experienced pain in your ears. That's caused by the air inside you being squashed - or by the change in pressure, to be more technical.

Even when you're not beneath the water your body is under pressure from the air. The invisible stuff around you, that you breathe in and out, has a weight. It's not very much, but when you're standing on the beach you're underneath about 35 kilometre of air (that's around 21 miles). That's a lot of air and it weighs about 2kg per square centimetre. All that weight is pushing down on your body all of the time - but you don't notice because you're designed to live in it.

Because water is a lot heavier than air, you don't have to go very deep before it begins to affect you - remember that pain in your ears when you dived to three metres? In fact, the pressure on your body doubles when you reach about 10 metres. Which means all the air in your body is squashed into half the space it usually takes up when you're on the surface.

Those first 10 metres are where you get the most dramatic change, as pressure doubles (or increases by 100%) from sea-level. At 20 metres the pressure is triple the pressure at sea-level, but it's only 50% more than the pressure at 10 metres. And so on downwards. Eventually, of course, it becomes unsustainable our bodies to cope, but by then we'd also be dealing with lots of other problems.

These changes have all sorts of implications for divers which is why training and practise is so important. At about three metres you might have a pain in your ears because of the change in pressure, but at 10 metres it could get much more serious.

For me, dealing with the pressure changes in my ears is the next serious hurdle to overcome. My first was being able to jump into the water and now I need to find a way to equalise the air pressure in my head as I dive. During both of my lesson my ears have hurt at the bottom of the diving pool (3 metres) and this week I still had minor ear problems over 24 hours after coming out. They've cleared now.

You're probably used to handling changes in air pressure - it happens when you come down from a hill or if you're in a descending aeroplane. I usually find that yawning or swallowing hard helps my ears to 'pop' or equalise. But you can't yawn under water and even swallowing is tricky. So I need to find another way.

I'm sure I'll find a way of dealing with it, and I'll have to if I want to dive deeper. But for the moment I do feel under a little more pressure than usual!