Wouter: Hit me with what you got. It's too cold for epoxy to set in my garage (latest kayak on hold) and too much snow to launch the T. Sewing machine just sits there while I am waiting for some pre-cut sail-kits..

pbisesi: It's not just the hook that can get caught, it's amazing what you can manage to get stuck to while sailing. Everything from sheets to trampoline lazing can tangle you, so you can never eliminate the danger completely. But having a quick release harness removes one of the larger risks. If the system is good enough, it should not release when you dont want it to.

I think the hose idea is too complex. First you have to get it down to the one trapped while he/she is still concious. Then he/she needs to remember how to use it correctly (in trough the mouth, out trough trough the nose) and dont hyperventilate in and out trough the hose. 99% (wild guess) of cases where you are trapped can probably be solved with a knife or rescue hook. Having a sealed mast with enough volume to keep the boat from turtling is the very best insurance against ever getting into such a situation.