Koh Rang National Park offers a diverse underwater landscape featuring reefs, pinnacles, and artificial structures including wrecks. Depths range from 9 to 30 metres, with an average of 15 metres. Access is by boat only, as the site is located 10 kilometres from shore. Conditions vary, with visibility between 5 and 30 metres and moderate currents that can strengthen quickly, especially around pinnacles. The site is suitable for intermediate divers and supports night diving. Guided tours are recommended to navigate the terrain and manage changing conditions. Hazards include sharp coral and stonefish, so maintain neutral buoyancy and avoid contact with the substrate.

Koh Thian is a small island located on the west coast of Koh Rang National Park. The site features two distinct topographies: a protected side with shallow, healthy coral reefs and an exposed side characterised by deeper, large rock formations and caves. Divers and snorkellers can explore depths ranging from 3 to 18 metres, with an average depth of 10 metres. Access is strictly by boat, and the site is suited for intermediate divers due to potential strong currents and surf. Visibility varies between 5 and 20 metres, and water temperatures remain warm throughout the year, typically between 29 and 31 degrees Celsius.

Koh Mapring Lek is a reef site located within Koh Rang National Park. Accessible only by boat, the site features depths ranging from 5 to 12 metres, with an average depth of 8 metres. Conditions are generally mild, with visibility typically between 5 and 15 metres. The water remains consistently warm throughout the year, ranging from 29 to 31 degrees Celsius. This site is suitable for beginners and supports both diving and snorkelling activities. Divers should remain aware of boat traffic in the area. A typical dive duration at this location is approximately 45 minutes.

Koh Tien is a shallow reef site located within Koh Rang National Park, suitable for beginner divers. The site features an average depth of 6 metres, with a total range between 3 and 10 metres. Access is strictly by boat. Underwater conditions are generally mild, though visibility can fluctuate significantly between 5 and 30 metres depending on local conditions. Water temperatures remain warm throughout the year, ranging from 29C to 31C. Divers should be aware of sea urchins present in the area. Typical dives at this location last approximately 40 minutes.

Hin Gra Dueng is a pinnacle and reef site located in Koh Rang National Park. The pinnacle rises from a depth of 30 metres up to 20 metres. Divers access this site by boat, and it is best suited for intermediate divers due to moderate currents. Visibility at the site ranges from 10 to 30 metres, though low visibility can occasionally occur. Water temperatures remain consistent throughout the year, ranging between 28C and 31C. The topography features a deep section that transitions into shallower areas as divers navigate around the pinnacle structure.

Hin Kuak Ma is a reef pinnacle located in Koh Rang National Park. Reached by boat, this site features depths ranging from 10 to 16 metres, making it suitable for beginner divers. The environment is characterised by mild currents and water temperatures between 29 and 31 degrees Celsius. Visibility fluctuates between 5 and 25 metres, often appearing clearest during morning hours. Divers should be aware that stonefish are present at this site, camouflaging against the reef and sandy seabed. To protect the environment and avoid injury, do not touch the reef or rest on the bottom. A typical dive duration at this location is 50 minutes.

Koh Yak Lek is a reef site located within Koh Rang National Park. The topography features a reef that circles the island, offering a variety of coral formations. Divers can explore depths ranging from 5 to 30 metres, with an average depth of 8 metres. Access to the site is by boat, as it is situated 1000 metres from the shore. Conditions are generally mild, with visibility ranging from 5 to 25 metres and water temperatures between 28 and 31C. This site is suitable for beginners and typically involves a 50-minute dive. Guided tours are available through local dive shops.

Koh Thian is a reef site located 1000 metres from shore in Koh Rang National Park. This site offers depths ranging from 5 to 15 metres, with an average depth of 10 metres. Access is by boat only. Divers and snorkellers experience mild currents and visibility between 5 and 20 metres. The water temperature remains consistently warm, between 29C and 31C. Due to the presence of jellyfish and sharp coral, wearing a wetsuit is recommended for protection. The site is suited for intermediate skill levels, and guided tours are available to help locate the most rewarding sections of the reef.