I believe the rule says the captain and crew can not keep their share of grouper. I.E. if there are 6 people and 1 captain and 1 mate (8 total); the possession limit for the boat is for 6 people. I believe the limit is 4 total groupers per person, so 24 total grouper only 6 can be gag or black; etc. Crew in the definition refers to only hired/working individuals.