Some have recently run into the FWC re-interpeting the rules for spearfishing on a charter in SE Florida. Last November several Jupiter boats were issued tickets for not having a charter fishing license even though the individual spearo's all had licenses. The arguement at the time was that it was a 'for hire' charter and the captain who is ultimately responsible (ie shorts, out of season, etc) for the fish brought onto his boat, needed a charter license to cover everyone and therefore insure the fish on board were all legal. In effect giving the FWC an avenue to charge the captain for non-compliant fish. Otherwise the captain could say he wasn't required to check all the catch since each person was responsible for their own. With no license required, can't issue a ticket to the captain. Unless no one would claim the non-compliant fish when the FWC boarded at the inlet, it would be a 'who dunnit'. If it's a short fish and no one claims it, who do you ticket? Definitely a loop hole.
The cases never went to court (which the victims wanted) so a clear definition could be established. But the FWC declined to pursue it. One of the key questions that is different from a Hook and Line charter is that divers 'get off the boat' and therefore are in 'possesion' of the fish individually away from the boat, meaning they need a license. It has still not been challenged infront of a judge for a clear decision that we can print on paper to show. I have not seen a formal letter issued by the FWC that we can hand to a boarding officer.
Right now most Jupiter charters have purchased a charter license at ~ $750 as well as requiring individuals to hold a valid license too. Just my own opinion, but if you are spearfishing, you better get a license to cover your individual self.