Thailand is one of the top diving destinations in the world and has some beautiful dive sites. I didn’t go to the Similan Islands which are listed in the Top 10 best diving sites but Ko Phi Phi and Ko Tao, the places where I dived, where already beautiful and totally worth it.
Diving in Thailand is very easy and cheap, Ko Tao being the cheapest place in the world to get your Open Water certification. Every island I’ve been to had tens of dive shops. No need to book long in advance either, 12h before being plenty enough. I didn’t dive in Lanta because it was more expensive. 2 dives in Phi Phi will cost you around 2500B whereas it will cost you at most 2000B in Tao. In the latter, you get a reduction the more dives you buy. 10 dives will cost you 7000B. Most diving resorts offer free accommodation in a dorm or reduced rates for better rooms the days you dive.
Unfortunately I fucked up camera wise and didn’t film anything on Phi Phi. Fortunately, I managed to film almost all my dives in Ko Tao.
As prices are the same in all dive shops of an island, pick a place where you fill the most comfortable with the people. It’s very important to get along with your instructor/divemaster, especially if you’re getting a certification. I got my SSI Advanced Aventurer at Big Blue which was great, everybody is really friendly there and the atmosphere is excellent.
As dive sites goes, I found Phi Phi more beautiful and saw more marine wildlife there. In 2 dives we encountered sharks, a turtle, lion fishes and many other. Ko Tao has still great dive sites. The Wreck was particularly nice. Visibility is a bit random as half the dives had poor visibility.
I loved diving in Thailand, it’s beautiful and affordable. What more could you ask?