I am a scuba diver, certified since 1972, but actually diving longer than that. I have collected my own aquarium fish since the late 60s, scuba diving and snorkeling in the Caribbean and in Florida, and also in the northeast, from Rhode Island down to North Carolina. Most of my local collecting is in NJ, for Gulf Stream tropical strays in late summer/early fall. We get lots of tropicals in NJ, including huge numbers of Butterfly Fish, Spiny Burrfish, Cowfish, Groupers, Seahorses, Lookdowns, Filefish, and occasional rarities. I have a Blue Angel about 3 inches long that I caught when it was less than an inch, 6 months ago while snorkeling in a NJ inlet. I've also got some Lookdowns and a Spiny Boxfish from last summer.
I really love Caribbean collecting, and take occasional trips to the Islands. I bring back a few fish, but you really need to know what you are doing, from where exactly to go, how to collect, the correct equipment (your aquarium nets are worthless), and how to maintain, pack, and transport the fish. Transportation is the biggest problem, especially since 9/11. The last Caribbean collecting trip I took was a year ago, to Jamaica during spring break. I managed to bring back a couple of fish, but it was tricky, with US airport security minutely examining my specialized collecting equipment on the way down, and Jamaican security my fish on the way back. US customs is not a problem if you enter through a designated port, like JFK and Newark, bring a declaration form, limit the number of fish to about 8 or fewer, and steer clear of corals, snails, and other possibly suspect inverts.