A warning to those of you who are trying to catch fish from a sailboat; do not try to land billfish. They can be extremely dangerous; I have personally seen a man speared through the chest by a large black marlin, though it was on a sport fishing boat.
Just get them as close to the boat as possible and cut the line. If you use steel (not stainless) hooks, they will corrode withing a short period of time and the fish will be unharmed, if hooked in the mouth.
"Any idiot can make a boat go; it takes a sailor to stop one." Spike Africa aboard the schooner Wanderer in Sausalito, Ca. 1964.