I've started a little research on Koh Tao. I plan on obtaining my DM around spring and interning a bit. I am wondering if anyone can tell me how the area diving, temp, vis, sea life and such, compare with Belize, Honduras, etc... I love Central America but I have heard great things about Thailand and thought I would give it a go.
To be honest, for the quality of diving, Tao isn't all that great in comparison with the west coast of Thailand. However, as a training area for DM work, you do get the chance to be a tank jockey quite a lot since the shops are busy, busy, busy! So it's a trade off cheap and busy in exchange for so-so diving. Having said that, you'll be just a hop away from much more interesting diving on the west coast. You don't say when in the spring you'll be coming, but you might consider jumping on a liveaboard to the Similans if you're here at the right time. The Similans National Park is open until May 1.
Water temps--around 82°F.
Vis--variable, but 30 to 50 feet is probably about average.
Marine life--Tropical reef fish, tunas, jacks, sharks, anemones, barracudas, sea snakes, stingrays, sponges, corals, groupers, turtles, nudibranchs, shrimps, lobsters, crabs, urchins, sea stars, sea cucumbers, and if you're lucky, whale sharks!
Comparison to Central Amercia My impression is that there are more sponges there in CA and less diversity of fish species. CA also has those trippy famingo tongue shells, which we don't have here.