Sounds like ISAF needs to come with an interpretation of this rule..

I still think it will be enforced (in whatever interpretation is given) as the RRS needs to be respected. If they make a new rule without enforcing it, what is the point of the new rule, and what then about the other rules.. Are they also optional? No, it will be enforced, but we need an interpretation of the rule.

However, getting trapped by your trapeeze hook underwater is just one of the possible scenarios. But as we have had one (several?) fatality, I can understand why they try to do something about this. Perhaps helmets and exoskeletons are next?

There are several quick release trapeeze hooks on the market , so most harnesses can probably be re-fitted (if this is what ISAF wants from the rule).

Ref: http://www.rwo-marine.com/newproducts.htm

(Mary, I checked, and could not find a similar product in the catsailor.com store, besides the Bethwaite one. I guess he will be livid if his system is not approved..)