Aardvark
Contributor
Where I live (NSW, Australia) you need a boat licence if you're going to skipper a vessel at 10 knots or more, except for PWC (jetskis, etc) for which a license is required at all times. Dive flags are covered in the handbook you need to study and it's your responsibilty to keep clear of swimmers (snorklers, swimmers and divers) in the water. Boats from which divers are diver must display the alpha flag and it's recommended for those diving from shore. If you find yourself cut up by a prop when diving in a waterway without a flag you're unlikely to get a lot of sympathy.
I'm a little puzzled by the objection to licensing. If your actions have no consequences for others then do what you wish, if you want to be in charge of a vehicle easily capable of causing injury or death then it's reasonable to ask that you prove you can operate safely, or at least understand the basics of safe naviagtion, before using it in public.
I'm a little puzzled by the objection to licensing. If your actions have no consequences for others then do what you wish, if you want to be in charge of a vehicle easily capable of causing injury or death then it's reasonable to ask that you prove you can operate safely, or at least understand the basics of safe naviagtion, before using it in public.