Don,
I don't know about FL, but up here in New England, Fish Spotters go out and spot Tuna for the tuna boats. They can spot the schools and direct the boats to the tuna; it takes most of the guess work out of the fishing. Certain kinds of tuna bring big bucks in Japan. We are talking in excess of $10,000.00 - $15,000.00 for one fish.
It is dangerous work; you are out there sometimes 200 miles off shore on one engine; Droning along low and slow for 8 ? 10 hours. The aircraft are usually modified with extra external fuel tanks and operated under restricted utility or experimental categories. Lots of new Commercial pilots take the risk as a way to build time.
Found this article on a quick search:
http://www.nytimes.com/books/first/s/safina-ocean.html
