Racha Noi is a marine dive site located off Koh Racha Yai, Thailand, offering a diverse topography of reefs, pinnacles, walls, and artificial structures. Suitable for intermediate divers, the site reaches depths between 2 and 40 metres, with an average depth of 25 metres. Access is exclusively by boat, as the site is situated 25 kilometres from shore. Divers should be prepared for moderate to strong currents, potential down currents, and boat traffic. Visibility typically ranges from 10 to 30 metres, with water temperatures remaining between 29 and 31C. Typical dive duration is 45 minutes.

Koh Keaw Nok is a reef site located off Koh Racha Yai, offering depths between 3 and 16 metres with an average of 10 metres. The site is accessible only by boat and is suited for intermediate divers due to moderate currents that can shift quickly. Visibility typically ranges from 10 to 25 metres. Divers should be aware of active boat traffic in the area and use a surface marker buoy. The reef structure features sharp coral and rocks, requiring careful buoyancy control. Night diving is permitted, providing an alternative perspective on the reef environment. Typical dive times are approximately 50 minutes.

South Tip at Koh Racha Yai is a diverse site featuring a mix of reef, wall, and artificial structures. Divers and snorkellers can explore depths ranging from 5 to 25 metres, with an average depth of 15 metres. The site is accessible only by boat and is suitable for beginners, though conditions include moderate currents. Visibility typically spans 10 to 30 metres. Water temperatures remain consistently warm, between 29 and 31 degrees Celsius throughout the year. Night diving is available at this location. Hazards to be aware of include boat traffic, jellyfish, and sharp coral. Comprehensive facilities are available, including equipment rental, air fills, and guided tours.

Buddha Island, also known as Koh Kaeo, is a reef site located 8 kilometres from Koh Racha Yai. The topography consists of rock formations covered in both soft and hard corals. This site is suited for advanced divers due to the presence of strong currents. Divers access the site by boat, with depths ranging from 8 to 15 metres and an average depth of 12 metres. Visibility at the site varies significantly, fluctuating between 2 and 15 metres. Water temperatures remain consistent throughout the year, typically between 29 and 31 degrees Celsius.

Yanui beach on Koh Racha Yai offers a shallow reef environment suitable for beginners and open water training. The site features a hard coral reef set against a sandy bottom, providing clear topography for navigation practice. Divers and snorkellers can expect depths ranging from 8 to 14 metres, with an average depth of 10 metres. Entry is made directly from the shore. Conditions are generally mild, though visitors should be aware of potential surf, strong currents, and the presence of sea urchins and sharp coral. Typical dives last around 45 minutes, and the site is accessible for night diving.

Barracuda Rock is a submerged pinnacle located off Koh Racha Yai, Thailand. This advanced drift dive ranges from 5 to 30 metres in depth, with an average of 15 metres. The site features a structure covered in hard and soft corals and sea fans. Due to the location, strong currents are common and can accelerate quickly around the pinnacle. Visibility is variable, ranging from 5 to 25 metres. Divers must use boat access to reach this site. Night diving is permitted. Given the potential for strong currents, low visibility, and sharp coral, this site is suited for experienced divers who can manage their position and maintain group contact.

Ao Sane beach on Koh Racha Yai offers an accessible shore dive suitable for beginners. The reef topography sits at depths between 6 and 14 metres, with an average depth of 12 metres. Divers typically experience mild currents and visibility ranging from 5 to 10 metres. The site is well-equipped with parking, toilets, showers, and a rinse station, alongside a local dive shop providing air fills and guided tours. Night diving is permitted here, offering a different perspective of the reef environment. Species recorded around this area include various moray eels, wrasses, butterflyfish, and lionfish. Be aware of sharp coral when entering and exiting the water.

Nui Beach on Koh Racha Yai offers a reef environment suitable for beginners, with depths ranging from 5 to 18 metres and an average of 10 metres. Access is via the shore, and the site features a beach club with toilets, showers, and a cafe. Divers and snorkellers should be aware of potential hazards including surf, jellyfish, sea urchins, sharks, and variable visibility between 5 and 15 metres. Currents are generally mild. Species recorded around this area include the black-orange dragonet, laced moray, titan triggerfish, checkerboard wrasse, white-eyed moray, powder-blue surgeonfish, brown butterflyfish, striped surgeonfish, white-spotted puffer, scorpionfish, bluespine unicornfish, blue-spotted urchin, snake eel, and dotted anemone crab.