Sail Rock is one of the best dive sites in the area. It’s a big granite pinnacle that breaks the surface halfway between Koh Pha Ngan and Koh Samui and as there are no other rocks around it acts as a congregation point for all the fish in the surrounding area.
The pinnacle drops down to 30 metres in the sand and is typically dived in a circular route around the rock, spiraling slowly shallower. If currents are strong however, dive masters will guide divers to the sheltered areas. There are other outer rocks a little deeper that can be seen from the main pinnacle and are home to reef sharks.