HTMS Phra Thong is an artificial reef and wreck site located 5000 metres from the shore of Koh Tachai. The site is suitable for intermediate divers, with depths ranging from 16 to 28 metres and an average depth of 22 metres. Access is by boat only. Divers should be aware of moderate currents and potential hazards including entanglement and sharp coral. Visibility at the site typically fluctuates between 10 and 25 metres. A standard dive duration is approximately 50 minutes. Water temperatures remain consistent throughout the year, ranging from 27 to 30 degrees Celsius.

Richelieu Rock is a limestone pinnacle in the Andaman Sea that reaches the surface only at low tide. The site features a reef and wall topography that descends to depths of 35 metres, with an average depth of 25 metres. Access is by boat only, as the site is located 45 kilometres from the shore. Divers should be prepared for moderate currents and occasional surf. Visibility ranges from 10 to 35 metres, and water temperatures typically sit between 27 and 30 degrees Celsius, though thermoclines can cause drops to 25 degrees Celsius. This site is suited for intermediate divers.

Hin Luang is a submerged pinnacle and reef system located 200 metres from Koh Tachai. The site features a wall topography with depths ranging from 18 to 45 metres, averaging 30 metres. Due to the strong currents and significant depth, this site is suitable for intermediate divers. Boat access is required for all dives. Visibility typically ranges between 15 and 30 metres. Water temperatures remain between 28 and 31 degrees Celsius, though thermoclines can create cooler layers at greater depths. Divers should be prepared for deep conditions and strong currents throughout the dive.

The Bon Soong Wreck is a sunken vessel located near Koh Bon, Thailand, serving as an artificial reef. Resting at depths between 12 and 20 metres, the site is accessible to divers with Open Water certification. The wreck structure provides an overhead environment, and divers should exercise caution regarding entanglement and local hazards including stonefish, lionfish, and sea urchins. Visibility typically ranges from 4 to 10 metres, with mild currents present. Boat access is required to reach the site, which is located 13 kilometres from shore. Guided tours are recommended to navigate the wreck layout safely. Night diving is permitted, offering a different perspective on the structure.

The Aquarium at Koh Tachai is a reef site offering depths between 3 and 14 metres, with an average depth of 8 metres. Suitable for beginners, the site features moderate currents and visibility ranging from 15 to 30 metres. Divers and snorkellers may encounter uncommon species including Day Octopus, Titan Triggerfish, Giant Moray, Harlequin Sweetlips, Spotfin Lionfish, Pink Skunk Anemonefish, Groupers, Painted Spiny Lobster, Brown Butterflyfish, Blue Dragon, Redtooth Triggerfish, Powder-blue Surgeonfish, Wrasses, and Bluefin Trevally. Entry is possible via boat or from the shore. Water temperatures typically remain between 28 and 31C, though rare thermoclines can lower this to 27C. Hazards include sharks, sharp coral, and strong currents. Showers are available on-site.

Bangsak Wreck is a former tin mining platform dredger that sank during a monsoon storm in 1984. Resting at an average depth of 16 metres, the site offers a wreck and artificial reef experience suitable for beginners. Divers access the wreck by boat, located approximately 13 kilometres from the shore. Conditions are generally mild, with visibility ranging from 5 to 12 metres and water temperatures between 28 and 30C. The site is managed with nearby facilities including equipment rental, guided tours, and boat charters. Divers should remain aware of boat traffic and currents during their 50-minute dives.

Koh Tachai Reef is a marine site featuring a combination of reef, pinnacle, and drop-off topography. Located 70 kilometres from shore, this site requires boat access and is suited for intermediate divers due to the presence of strong currents. Depths range from 5 to 40 metres, with an average depth of 25 metres. Visibility varies between 10 and 40 metres, and water temperatures remain warm throughout the year, typically between 28 and 31 degrees Celsius. Divers should be aware of hazards including deep water, strong currents, and sharp coral. Night diving is permitted at this location, with typical dives lasting 60 minutes.

Boonsung Wreck is an artificial reef site located 5000 metres from shore near Koh Bon. This wreck dive sits at an average depth of 17 metres, with a total depth range between 14 and 18 metres. Access is by boat only. Conditions vary, with visibility ranging from 5 to 25 metres and mild currents. The site is suitable for beginners and supports night diving, with typical dive times around 60 minutes. Divers should be aware of hazards including entanglement, sharp structures, and potential encounters with lionfish, stonefish, and sea urchins. The habitat supports a variety of reef fish and invertebrates typical of the Andaman North region.