Marlas Mystery Wreck is an artificial reef located at Koh Racha Noi, Thailand. The site sits at depths between 26 and 34 metres, with an average depth of 32 metres. Access is by boat only. Divers encounter mild currents and visibility ranging from 10 to 30 metres. The wreck features sharp edges and overhead environments, requiring careful buoyancy control and kit configuration to avoid entanglement. Due to the depth, this site is suited for advanced divers, and wreck certification is mandatory for internal penetration. Divers should monitor gas management closely and remain near their guide. Hazards include decompression risks, nitrogen narcosis, and sharp structures.

Homerun Reef in the Racha Islands is a diverse dive site featuring a combination of natural reef, artificial reef structures, and a wreck. Suitable for beginners, the site offers depths ranging from 3 to 25 metres with an average of 15 metres. Access is by boat only, as the site is located 20 kilometres from the shore. Divers may encounter moderate currents and visibility between 10 and 30 metres. Water temperatures remain warm, typically between 29 and 31 degrees Celsius. Hazards include entanglement risks, sharp coral, and strong currents. Species recorded around this area include sea kraits, giant morays, titan triggerfish, reef stonefish, and Indian lionfish.

Staghorn Reef at Koh Racha Noi is a versatile site featuring a mix of reef, drift, and artificial structures. Divers and snorkellers can explore depths ranging from 5 to 30 metres, with an average of 15 metres. The topography includes branch coral clusters, rocky areas, and walls. Due to moderate currents, this site is well-suited for drift diving. Access is strictly by boat. Visibility typically ranges from 10 to 30 metres, and water temperatures remain warm between 29 and 31C. Species recorded around this area include various moray eels, lionfish, triggerfish, and pufferfish. Hazards include boat traffic, jellyfish, sea urchins, sharks, sharp coral, stonefish, strong currents, and surf.

Lucy's Reef at Koh Racha Noi offers a diverse underwater environment featuring a mix of natural reef, artificial structures, and wall topography. Extending from Bay 3 to Bay 4, the site ranges in depth from 3 to 35 metres with an average of 12 metres. Divers and snorkellers can explore coral beds and rocky formations. Access is by boat only, and the site is suitable for beginners. Conditions include mild currents and visibility between 10 and 30 metres. Species recorded around this area include giant moray, reef stonefish, titan triggerfish, and sea krait. Hazards to be aware of include boat traffic, rip currents, sea urchins, sharp coral, stonefish, and strong currents.

Bungalow Bay, located on the western side of Racha Yai Island, offers a diverse underwater environment featuring a reef, artificial reef, wall, and wreck. With depths ranging from 5 to 25 metres and an average of 10 metres, the site is well-suited for beginners. Access is exclusively by boat, with the site situated 1000 metres from shore. Divers and snorkellers can expect mild currents and visibility between 8 and 50 metres. The site is protected from easterly weather, making it a reliable location for training and recreational diving. Hazards include boat traffic, jellyfish, lionfish, sea urchin, sharp coral, and stonefish. Night diving is available, with typical dives lasting 50 minutes.

Siam Bay, located at the northern end of Racha Yai, features rocky edges surrounding a central sandy area interspersed with hard coral patches. The site is notable for its artificial reef structures, including two elephant statues and a temple gate guarded by a mythical giant sentry, positioned between 18 and 20 metres. Diving depths range from 3 to 30 metres with an average of 15 metres. Access is by boat only. Conditions are generally mild, though strong currents can occur. Species recorded around this area include Indian lionfish, giant moray, reef stonefish, and titan triggerfish. Hazards include jellyfish, sharks, stonefish, and strong currents.

Kon Kare Bay at Koh Racha Noi offers a diverse underwater environment featuring a combination of natural reef, artificial reef structures, and wall topography. The site is suitable for beginners, with depths ranging from 5 to 30 metres and an average depth of 10 metres. Divers and snorkellers can expect mild currents and visibility typically between 15 and 30 metres. Access to the site is by boat only. Water temperatures remain consistent throughout the year, ranging from 29 to 31 degrees Celsius. Stonefish are present at this location, so caution is advised when navigating the seabed.

Waterfall Wall at Koh Racha Noi offers a combination of reef and vertical wall topography. Divers typically explore depths between 14 and 25 metres, with an average depth of 20 metres. The reef structure features staghorn, brain, and pore corals alongside soft coral patches. Visibility varies significantly from 5 to 30 metres. While currents are generally mild, they can strengthen without warning. Hazards include jellyfish, lionfish, stonefish, sea urchins, and sharp coral. Divers should shuffle their feet in the shallows to avoid stonefish and maintain distance from the reef face. Guided tours and air fills are available on site, and night diving is permitted.