I just come back from Thailand and Bali last january.
I did 4 dives in Bali and Thailand and it was AMAZING.
I´m a begginer, 13 dives before there, and I could see a lots of fishes, anemonas, ship recks, jaws, seahorses etc.
I had a dive in Krabi, especialy at Koh Si.
In Bali I dived at Tulambem, the best one, I will never forget that dive and in both cases the visibility was perfect.
Fernando - Brasil

Thanks for your input, Fernando. it sounds amazing!

We're debating between Krabi, Phuket or Khao Lak for diving. Khao Lak seems to be the closest if we want to dive the Similans, but I don't know if we would be better served staying in either Krabi or Phuket.

Anyone have a suggestion?

Yeah, I agree that Similan is great place for scuba diving. Lovely Coral Reef.

But where would you stay?