Sail Rock is the most famous dive site near Koh Samui, located about an hour away by boat. It’s renowned for its towering underwater pinnacle that rises from 30 meters deep to just below the surface. Divers often spot large schools of barracuda, mackerel, and sometimes even whale sharks.

Known for its deeper dives, Chumphon Pinnacle is a favorite among advanced divers. This submerged granite pinnacle is covered in soft corals and anemones, attracting large pelagic species like barracudas, groupers, and reef sharks.

Located near Koh Tao but accessible from Koh Samui, Shark Island is named for its shark-fin shape above water, not because of sharks swimming below (though reef sharks are occasionally seen). The site boasts colorful coral gardens, an abundance of reef fish, and occasional turtle sightings.

Ang Thong National Marine Park offers diverse diving opportunities, with numerous small islands featuring caves, tunnels, and swim-throughs. While the marine life isn’t as prolific as other sites, the unique rock formations and landscapes make for an unforgettable dive.

Southwest Pinnacle is a cluster of submerged pinnacles located southwest of Koh Tao and Koh Samui. It’s known for its abundance of anemones, attracting schools of batfish, barracuda, and occasional sightings of whale sharks.

Situated near Koh Phangan, Koh Ma offers a gentle dive experience with beautiful coral gardens and a variety of smaller marine life. It’s an excellent spot for beginners to practice buoyancy and explore shallow coral reefs.

A lesser-known but beautiful dive site, Hin Ngam features rocky reefs and an abundance of soft corals. The marine life here includes various reef fish, moray eels, and nudibranchs, making it a great site for macro photography.

Located near Koh Nang Yuan, Green Rock is famous for its swim-throughs and exciting rock formations. The marine life here is diverse, with pufferfish, angelfish, and even the occasional blacktip reef shark.