Koh Usen is a reef site located off Koh Adang, Thailand, suitable for both diving and snorkelling. The site features a consistent depth of approximately 8 metres, making it an accessible location for beginners. Entry is via the shore, and divers can expect mild currents and visibility ranging from 10 to 20 metres. Water temperatures remain warm throughout the year, typically between 29C and 31C. Night diving is available at this location. Hazards to be aware of include boat traffic and sharp coral. Species recorded around this area include wrasses, butterflyfish, parrotfish, anemonefish, groupers, moray eels, sea kraits, and spiny lobsters.

Ao Taloo Lancha is a reef site located off Koh Adang, Thailand, offering a shallow environment suitable for beginner divers. The reef features a mix of hard and soft corals across depths ranging from 5 to 14 metres, with an average depth of 9 metres. Divers typically experience mild currents and visibility between 10 and 20 metres. Access is by boat only, and divers should remain cautious of sharp coral formations and surface boat traffic. With water temperatures consistently between 29 and 31 degrees Celsius, the site provides a comfortable setting for 45-minute dives.

Zero Rock is a submerged pinnacle located off Koh Adang, offering a straightforward structure for divers. The site ranges from 5 to 25 metres in depth, with an average of 12 metres, making it suitable for beginners. Divers can explore the pinnacle, which features soft corals, sea fans, and sponges. Conditions vary, with visibility between 5 and 25 metres and moderate currents that can strengthen unexpectedly. Boat access is required to reach this site, which sits 25 kilometres from shore. Due to regular boat traffic in the area, divers must deploy a surface marker buoy before ascending. Be aware of stonefish resting on the bottom and avoid touching rocky surfaces.

Koh Yang East is a reef site located 1000 metres from the shore of Koh Adang. Divers typically experience depths ranging from 5 to 24 metres, with an average depth of 18 metres. The site is accessed by boat and is suitable for beginners, though conditions can include mild currents and surge. Visibility varies significantly, ranging from 5 to 30 metres. Water temperatures remain consistent between 29C and 31C throughout the year. Hazards at this location include jellyfish, lionfish, sharp coral, stonefish, and strong currents. Species recorded around this area include wrasses, butterflyfish, anemonefish, parrotfish, sea kraits, titan triggerfish, and giant morays.

Waterfall is a muck and reef dive site located 1500 metres off Koh Adang, Thailand. The site features depths ranging from 6 to 19 metres, with an average of 15 metres, making it suitable for beginner divers. Access is by boat only. Divers encounter mild currents and visibility between 10 and 25 metres. The topography consists of small coral patches that provide shelter for various marine life. Divers should be cautious of sharp coral and rocks. Species recorded around this area include wrasses, groupers, butterflyfish, and anemonefish. Night diving is available and recommended for observing cryptic species that hide in crevices during the day.

Koh Yang, located off Koh Adang, offers a diverse underwater landscape featuring a reef, wall, and pinnacle. Divers can explore depths ranging from 5 to 30 metres, with an average depth of 18 metres. Visibility typically spans 10 to 30 metres. Access is by boat only, and the site is suited for intermediate divers due to moderate currents and potential surge near the structures. Divers should plan their entry around tidal timing to manage current strength. Species recorded around this area include wrasses, butterflyfish, parrotfish, anemonefish, surgeonfish, sea kraits, titan triggerfish, giant morays, and painted spiny lobsters.

Honeycomb Beach on Koh Adang offers a combination of reef and muck diving, suitable for beginner divers. The site features depths between 5 and 15 metres with an average of 10 metres. Divers experience mild currents and visibility ranging from 5 to 20 metres. Access is by boat, and divers should note the presence of a shore break during entry and exit. The topography includes reef sections interspersed with sandy patches. Divers should remain aware of jellyfish in the water. Guided tours are available for those seeking assistance in locating specific marine life within the reef and sandy areas.

Koh Jabang is a pinnacle reef site located near Koh Adang. The topography consists of a submerged pinnacle offering a drift diving experience with depths ranging from 3 to 30 metres, averaging 16 metres. Due to strong currents, this site is suited for intermediate divers and requires boat access. Visibility typically fluctuates between 10 and 30 metres. Species recorded around this area include wrasses, groupers, butterflyfish, and anemonefish, alongside the Magnificent Giant Anemone. Night diving is available at this location. Divers should be aware of hazards including strong currents, potential for nitrogen narcosis, and decompression requirements.