I started out on dinghies as a kid, moved to dayboats, spent time learning how to operate single screw and twin screw power boats, gained RYA qualifications for both Power and Sail, and learned navigation from first principles before GPS was common, and have chartered many times in the BVI and elsewhere, but I still take great comfort from guidance and instruction.

Seriously - my guess is that there are quite a few charterers (and maybe some owners?) that are not so frequent in their use of 40-50ft sailing cats as some locals may be. Given that, recognizing the limits of ones capability in dealing with local freaky weather, gear failure, grounding, collision, close quarter maneuvering etc and thinking that additional instruction from time to time to polish skills would be beneficial can only be a good thing - right? Doesnt really matter wether the rules say you have to or not.

I know it helps me!