There are many ways to answer this question, but most guides agree that a tip is appropriate if you fish with a hard-working guide, partner, or captain. Voyager Deep Sea Fishing %26 Dolphin Cruises said you should always give your waiter the same thing you would give your partner. Only large offshore ships will have more than one sailor and it's common enough that you know how to handle it. With two sailors and a captain in charge of the trip, tips can be confusing and the breakdown of the tip differs from ship to ship.
Gratuities of 20% of the trip price are standard on large ships and tips will be divided among the three crew members as they see fit. Tipping individually is a great way to show appreciation, but on some ships, it's customary to tip 20%, with 10% for the captain and 5% for each sailor. On other ships, the captain is paid enough of the charter rates that all tips go to his sailors. If you are worried about making a mistake, you can always ask if you should give an individual tip or a lump sum to the boat and they will gladly inform you.
In a group setting, anglers can split tips, but they help your fishing partner with advanced knowledge to prevent them from feeling embarrassed at the end of the fishing day. When a fisherman has a fish on, it is the sailor's job to help during the fight before reaching out, gaffing, or tying the fish's tail to get it on board. At the end of a fishing trip, when you return to the dock, it's your turn to take care of the good fishermen who took care of you.