Tuna Boats
Its been a few years but their used to be an operator at a small airfield called Pateia?? He is an american and maintained a load of different helicopters for the boats.
Before venturing down there I would start a phone search and talk to a few people first. Try to find an American boat, the living conditions, food and helicopter all will be to an acceptable standard (well better than the alternative). Stay away from Guam and the Korean fleet unless you really wish to be treated like dog dodo. Search here for "Tuna Boat" and I think it will bring up a number of threads. Try Gann Industries in San Diego, they have (or did) 4 or 5 boats and a large number of crew and skippers live in that area. Get a copy of HAI Helicopter Annual and look up Panama for operators, call and if they don't handle the helicopters they may know who does.
Lastly if you are of a sensitive nature you may not be ready for the verbal abuse that will be screamed at you during a set, or even worse you become unservicable at sea and cant fix it, then you will be the pirrana of the ship. As to the flying slightly on the cowboy side and a lot of low tight manuvours not for the fainthearted. Landings and takeoffs can be a "challenge" and have more than their fair share of accidents. Old advice but walk around twice to check the chains are off the skids before you T/O, when landing cross the bow left to right, make a right turn let the ship pass you and match the speed on final. Fixate on the landing spot as you touchdown, dont use the horizon as the leveler, remember you are rising and falling with the ship and get the collective down asap. If you dont have a mechanic with you then train one of the crewmen to chain you down and refuel you.
I'm sure I have missed something but the old farts brain can't retain old info or water for that matter.
Best of luck to you anyway, if you'r single and can put up with your own company for months at a time and dont mind a little discomfort sometimes then it can be an adventure.