Scuba diving in Koh Tao is actually quite good but can't compete with the world class dive sites of the Andaman sea like for example in Koh Lanta , Koh Phi Phi or Similan and Surin Islands . Whale Sharks are sometimes spotted around Koh Tao, and on offshore dive sites like Chumphon Pinnacle , it is possible to see Bull Sharks . It is actually one of the few places in the world where it is possible to spot them from up close. They have been misidentified for a long time as Grey Sharks . Bull Sharks can be curious, and sometimes aggressive, but in years of diving on these sites, there hasn't been any problems reported of attacks or the like.