With over 16 beaches, Koh Samet has many decent underwater sightings for the diver in you. Although not as famous as Koh Tao for diving, Koh Samet does have some beautiful seascapes. Some well-known sightings are pufferfish, stingrays and some rare black-tip sharks.
The corals are extremely impressive too. The visibilty ranges between 5-10 metres. There are open-water and PADI courses offered by popular diving schools like Ploy Diving and Ao Prao Divers.