I have wondered the same thing. I read it the same as you, has to be worn while in the rapid. I would be surprised if someone were ticketed for not having a life jacket on but maybe.
Another law I have wonder about;
All boats 16 feet or longer, must carry one Type I, II, III or V for each person on board and one Type IV throwable in each boat. (*Note - canoes and kayaks are exempt from carrying Type IV throwable flotation device.)
Does this mean a 16+ raft or cat needs a cushion to throw?
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