Ko Sak is one of the most frequented islands by many dive boats as well as snorkel tours and traffic around here (including that of jet skis) can be a bit busy.

Although on some days the visibility may not be as good as found at the far islands, Ko Sak offers a number of treasures, like the Ko Sak turtle, ghost pipefish and the small white ribbon eels, all at very convenient shallow depths. Also, look out for some of the artificial reef projects located in several places.