Monday, June 28, 2010

Beware Scuba Diver - Hand Signals Only

I forgot something really important the last time I dived.

Hand signals. It's bugged me that during my first dive in the sea I neglected one to follow one of the most basic procedures in scuba diving. When you enter enter the water and when you surface after a dive the first thing you should do is indicate to the boat crew that you're okay, using a recognised hand signal. I forgot.

My neglect was sort of excusable. Learning to dive is a bit lit learning to drive. There's so much to remember that you wonder how anyone manages to appear relaxed while doing it. I forgot to use hand signals because I had too much to think about.

While it's a great excuse, it's not something I want to repeat. Failing to signal your intentions when driving could lead to difficulties. Failing to signal when diving isn't quite as risky, as no one's likely to run into you as you perform an unexpected manoeuvre. But it's good practice to let the dive team on the boat, and your buddy, know that you're okay.

Successful diving relies on use of hand signals. They're the main form of communication what you're underwater. I was taught early on about the importance of the 'I'm okay' signal, which isn't a thumbs up, as you might expect.

The 'I'm okay' signal is both a question and a statement. When you give the sign to your buddy you're saying 'I'm okay, how about you?' and it prompts a response - usually 'I'm okay'.

This isn't the place to go into a list of hand signals, and it appears that they vary between the different diving groups. Suffice to say, a good grasp of the basic signals is important and they should be discussed with your buddy in advance, to reduce the risk of potential misunderstanding later.

Tuesday, June 8, 2010

It's Always Safety First in Scuba Diving

Scuba diver training can be very frustrating.

No one learns to dive because they want to lurk at the bottom of public swimming pools, where the only 'marine life' are the spiders and other insects who've fallen in. But for the first few weeks that's where we spent our time and I suspect most other divers do the same.

In this bland, tiled environment I was put through a series of exercises and drills that weren't what I signed up for. My ambitions for scuba diving were swimming along the seabed watching the antics of fish, crabs and other creatures in their own habitat. I wasn't terribly interested in learning how to recover a buddy who's in trouble, switch to using my buddy's emergency regulator or, my least favourite, clear a mask full of water.

But tiresome though they may be, familiarity with dealing with these situations is vital. For all the fun and wonder to be had in scuba diving, you mustn't forget that you're in a potentially hostile environment. Humans weren't designed to live underwater and when something goes wrong it's easy for a minor problem to escalate into a very serious issue with potentially deadly consequences.

I discovered this for real during a recent dive off Swanage. It was only my second dive in the sea and my first to a depth of 12 metres and I was still feeling very reliant on my buddy for guidance.

So I was surprised to turn around and find he'd vanished. We'd been drifting along the seabed and I'd got slightly ahead of him. Visibility wasn't too bad - probably about 5 metres, perhaps a little more, and we were reaching the end of our agreed time underwater.

Every minute or so during the dive I'd checked that he was nearby. This can be harder than it sounds when you're diving - your field of vision is restricted so it can take a moment to do a full 360 degree sweep. It was a good few seconds before I accepted that he really wasn't nearby.

A train of thoughts rushed through my head. I was alone at the bottom of the sea, being pushed along by the current. The dive boat could track my buddy's position because he had an SMB (surface marker buoy) but I didn't. If I moved too far from them when I surfaced I'd simply be a tiny black speck in the sea, difficult to spot from a distance. These were unhelpful thoughts which, if left unchecked, could lead to anxiety and panic.

Common sense kicked in. I still had a plenty of air and the first thing to do was the separation drill. I was already satisfied that I couldn't see my buddy from the seabed, so I rose a couple of metres and checked again. He still wasn't in sight. My training said I should now surface.

This is where I faced a dilemma. Rising from a depth of 12 metres I should have performed a safety stop at 6 metres, floating for 3 minutes to help ensure correct decompression. It's not a mandatory requirement but it's recommended best practice. I'd have needed to be at that depth for a lot longer before a stop became an absolute requirement.

I decided that my concern about drifting away from the boat overrode my need to do a stop. Another principle I'd picked up from training was that in an emergency the most important thing is to get to the surface - other issues can be dealt with after that. Okay, this wasn't exactly an emergency, but it was a 'situation'.

The good news, as it were, was that I was able to surface without injecting any air into my BC (jacket). Another valuable lesson from this dive had been about controlling buoyancy with minimal use of the BC inflation controls. That can be the subject of another blog post and suffice to say I was able to float to the surface easily.

When I got there the boat, and my buddy, were nearby.

In hindsight I wish I'd done a stop. Not only would it have taken away lingering concerns about decompression, but it would have allowed me to stay observe the surface from under the water. While the vis at 12 metres wasn't bad, as I approached the surface my vision became a blur of bubbles and light. For the last few seconds I couldn't see where I was going and no longer felt in control. I raised my arm to protect myself from an encounter with the boat, just in case.

It turned out that my buddy, a much more experienced diver, had suffered a free-flow which had caused him to surface suddenly. So I hadn't simply moved too far from him underwater; he'd run into difficulties and been forced to surface immediately, at a moment when I hadn't been watching him.

To be honest, if I'd seen him suddenly shooting upwards I would probably have been even more concerned.

Learning to dive is a bit like learning to drive. When you start there's so much to think about you wonder how anyone manages to make it look effortless. But over time more and more becomes second-nature. This is why all those safety drills in the pool become so important - if the unexpected happens you need to know what to do and have the confidence to make decisions for yourself.

Diving instructors can't deliberately put trainees into mildly challenging situations, but if they happen it's a powerful learning experience. It's made me think through a number of issues, including what I'd do differently next time and whether I should carry my own SMB in future, just in case.

As we went through all those frustrating drills in the swimming pool our instructor kept telling us that it's unusual for something to go wrong during a dive. But as my experience in Swanage proved, it does happen, and that's when you realise the value of all that preparation and practise. It might be frustrating, but it's not a waste of time.

Sunday, June 6, 2010

Ocean Diver (Almost)

I'm taking the BSAC Ocean Diver course.

So it's appropriate that yesterday's diving was in the ocean. Or to be more precise, the English Channel. Or to be even more precise, Swanage Bay.

During my various visits to Swanage I've watched the dive boats coming in and out with mild curiousity. Where do they go? What do they do? So there was some satisfaction in being part of the team loading a boat on the beach, watched by casual observers on the promenade. How many of them harboured a latent desire to be joining us, as I always had?

The Alton BSAC club is fortunate enough to own its own RIB (rigid-hulled inflatable boat) courtesy of a National Lottery grant. It was large enough to carry the six in our party to our two dive sites, the first of which was just off Swanage's west beach.

Diving in the sea brings it's own challenges. First there's buoyancy - a novice diver needs to carry more weight because it's harder to sink in salt water. Secondly, the suface is constantly moving because of wave action. In a busy harbour there's also plenty of surface disturbance from other boat users.

Performing my first backwards roll entry into the sea was relatively easy - I've got used to the idea of falling into water and assuming that I'll eventually surface. I just concentrate on breathing and natural buoyancy sorts out everything else.

My main problem was overcoming this buoyancy and getting below the surface. On the first dive I was carrying 10kg in weight and could not get down. My buddy added another 2kg to my pocket and at the same time I remembered what my instructor had said about tension creating buoyancy problems. As I floated on the surface I told myself to relax and allowed the waves to wash over me. It did the trick and moments later I was 6m down, on the seabed.

I learned a huge amount from my two ocean dives and it's given me plenty to blog about in the coming days. I had my first encounter with marine life, my first dive to a wreck, my first drift dive and my first underwater incident that proved the importance of all our safety training.

It's also left me with some important decisions to make. Do I buy a wetsuit or a drysuit? Should I invest in an SMB (surface marker buoy)? Is this the right time to buy a dive computer?

Lots to think about and lots to write about. I'm not a qualified Ocean Diver yet, but at least I've now dived in the ocean!