Saturday, May 7, 2011

Frequent practice can't go wrong

What an evening for practice! Land temperature was 20 degrees when I left work, so I could not pass up an chance to join the regular practice group. The nice weather also brought out beach combers and a lone diver/snorkeller.
Water temperature was still very low. The location and timing seemed a great chance to practice strokes, a few rolls, rescues and reentries. It occurred to me later that frequent exposure to cold water, even though we are all wearing dry suits may also be a useful means of increasing the body's sensitivity to cold immersion. A lot has been written about cold shock and I don't know if there is solid physiological evidence to support this, but it seems to make intuitive sense. What is not known is whether you will react the same way every time - so another good reason to paddle with 1-2 folks.

According to one resource:
Cold shock occurs immediately - as you enter the cold water. It lasts three to five minutes but it can result in quick drowning because of the way the body reacts. You cannot control these reactions:
A large intake of breath
A rapid increase in breathing rate (up to four times as fast)
A reduced ability to hold your breath (to as little as 10 seconds)
A massive increase in heart rate and blood pressure

A significant factor seems to be reducing exposed skin - I added a cap over my thermal head protection. Tony wears a helmet which I think further increases thermal protection and also reduces risk of injury by another boat while in the water. And hand protection is a good idea, I couldn't get a mitt my size, so I settled for using a glove made by Brooks that has a leather palm, but is also neoprene - while waiting on an order.


Tony said...

Mike, I fully believe you can control the gasp reflex if you practice cold water immersion and wear proper attire.

I improved my roll this pat winter in the pool to a point where it was effortless. My first roll in the sea this spring was hurried and felt jerky, not at all smooth. The issue was the 1 degree water. In the last several weeks I've spent a lot of time under water in the cold and now it doesn't affect me as much.

I also wear a helmet not for the cold but to keep me from looking too much like a mad butcher with my neoprene skull cap on!

Tony :-)

michael said...

Good points Tony - it seems a lot of research has been done on folks without protection>
The more we practice and mentally rehearse the lower the risk.