D.O’s Corner

The Diving Officer’s Corner is a dedicated section for the current D.O to post notes and observations for club members on safety and planning issues.

MARCH 2011

D.O’s Review by Gary Coles:

With the dive season fast approaching, it’s time to start doing some housekeeping for the forthcoming dive season and to ‘Think Safety’.

Diving Fitness and Kit

Firstly, are you fit to dive? Have we put on a few extra pounds over the winter? You do not want to pull a muscle lifting heavy dive kit or worse. Is your kit serviced and ready for the season?

Skills

Are your skills practised and up to date? I know we have an Ocean Diver Course and a Sports Diver following at the moment, so talk to Paul Phillips find out if there is room for you to get in the pool with your kit (and a buddy) to brush up on those skills.

BSAC Incident Reports

Check out the BSAC website - the latest statistics for incidents reported in 2010 are posted there for you to download. It makes good reading and opens your eyes to what happens in different scenarios.

Also there is a new manual called ‘Safety & Rescue for Divers’ - if you have some spare pennies why not give it a read?

Info for SSAC members

And finally, to make you all aware - to dive with us this year, I must have a completed and up to date Medical Form in my possession, you must be a member of BSAC (unless diving as a guest with our club which is chargeable on top of fuel fee’s for boat and tow) and you must also be an SSAC member (again unless diving as a guest).

There will be no exceptions to this so if you are unsure about anything, please check with our membership secretary Anne Trigg, whose email address is listed here in our Contact section.

JANUARY 2011

D.O’s Review by Ed Lomas: 

Incidents and common problems in the 2010 season

The main problem areas have been buoyancy control, nitrogen narcosis, and use of pony cylinders. Diving in threesomes continues to be a worry, but has generally been handled well when needed. Dive planning has improved a lot, but there are some issues.

Bouyancy Control

If you have suffered a fast buoyant ascent more than once in the last two years, have to swim hard all the time, or find that you are using much more air than other divers of your build and grade – then you have a buoyancy control problem.

Stop denying it. Practice breath control on the surface, breathe out until it is uncomfortable, breathe in slowly until it is uncomfortable, breathe right out slowly again, then try stopping half way and so-on.

Why? Because you may be keeping your lungs almost full while you are underwater, which prevents you from achieving proper neutral buoyancy.

Now, do the buoyancy check properly, normal kit, cylinder with less than 50bar, try it 3m below the surface, with an instructor or well qualified buddy watching you. Breathe out and sink, breath in and rise.

Dry suit problems may be making buoyancy control difficult. Some divers who should know better have been saying there is a debate about using the BCD for buoyancy control, rather than just the dry suit.

No. There is no debate, and this piece of nonsense has made it hard for some trainees to master buoyancy control, putting them at risk. Experienced divers who do this are welcome to continue, but unless you are carrying heavy kit it is pointless.

All you are doing is counterbalancing lead that you don’t need. No debate, read the buoyancy control workshop notes, dry suit course notes, and the safe diving pages. They all say the same thing.

Fast ascents are risky for you and use up the emergency oxygen!

Nitrogen Narcosis

On the Scapa trip, some of our party suffered panic attacks and disorientation below 30m. Fortunately they coped with this and mastered the panic, but it could have been much worse. The warship wrecks are deep, dark and visually confusing.

It is important to remember that nitrogen narcosis is always there, but the effects can be managed simply by gaining experience and adjusting to them, as long as you don’t try to go far too deep.

Please don’t imagine that going for a quick trip down to 35m in an easy environment means that you will always be OK at that depth. If you can’t build up your depth gradually past a certain point, because you don’t have access to any deeper water.

Try increasing the task loading in some way that does not affect your immediate safety, like writing notes, knot tying or playing with mechanical puzzles.

Pony Cylinders

These are supposed to make you safer! There have been a couple of incidents where changing over to the pony cylinder has gone wrong, leading to a quick swim to the surface, and one case of a diver keeping the manifold of a twin set open although he had difficulty doing a shut-down (don’t worry if you don’t understand this).

If you use a pony or a twin set, you should be well practised and completely confident about swapping regulators. If you aren’t, take every safe opportunity to practice.

Make sure all your DVs are really distinct, including the AS valve, so that you know which is which.

Make sure both cylinders are turned on at the start of the dive, check that both sets are giving air freely (buddy check). Turn the flow setting of the pony DV down, if it has that control, remember to open it up after changing over.

It is probably not a bad idea to experience breathing a cylinder right down, in the swimming pool. This will show you that ‘running out of air’ is a gradual process, and that you can inflate a BCD or drysuit even after it has become noticeably harder to breathe through the DV.

Threesomes

Always try to avoid this. If you have to, least and second most experienced divers work as a buddy pair, most experienced diver follows the buddy pair, whose leader checks on the most experienced diver regularly, but concentrates on the least experienced diver.

Don’t dive as a threesome on deep or demanding dives, ever. The task loading is high enough anyway.

Dive Plans

This continues to worry me, though no incidents so far. The basic plans are usually fine, but the alternative dives do not get enough thought.

It is a really bad idea to abandon the main plan, because of bad weather or whatever, and then go for an alternative that is possibly more difficult, without adequate planning.