I am no expert here, but I think most of the regulations state possession, so it would seem that if you give the fish away, you are no longer in possession. Probably cannot do it once you have kept your limit, because technically you would have to possess the fish before you gave it away and at that point would be in violation, but as long as you stay 1 short of limit I don't think that would be a problem ( but I won't pay your fine if I am wrong ).
My experience with boats out east is that they take the number of people on the boat and keep two fish for each person and then divide up the filets unless any one person asks to keep his own fish, and then they oblige. This is however not really legal, as they always count the crew and that is not permitted. Only customers can keep two fish, crew can keep none, that was the trade off for the two fish limit. When it was one fish I believe you could count the crew. You must keep your receipt as the DEC often checks on the way home from Orient or Montauk because it is so easy with the limited number or roads.