HTMS Hanhak Sattru is a decommissioned naval vessel resting at depths between 13 and 24 metres near Koh Nang Yuan. As an artificial reef, the wreck features a complex superstructure that requires steady buoyancy control due to moderate currents. Visibility typically ranges from 14 to 30 metres, allowing for clear views of the vessel. The site includes enclosed sections that present an overhead environment, necessitating caution and the use of a dive torch for those entering the hull. This site is suitable for intermediate divers, with boat access required for all visits. Night diving is available, offering opportunities to observe nocturnal activity within the structure.

Laem Thian Pinnacle is a shore-accessible site near Koh Nang Yuan featuring a combination of pinnacle, reef, and cave topography. Divers can explore depths ranging from 5 to 35 metres, with an average depth of 18 metres. The site is subject to moderate currents, which can create drift conditions and occasional rip or down currents around the structure. Visibility varies significantly between 8 and 30 metres. The cave section presents an overhead environment that requires careful navigation. Shore entry requires assessing the surf conditions before entering. Due to the depth and current conditions, this site is suited for intermediate divers with strong buoyancy control.

Mao Bay at Koh Nang Yuan features a combination of natural reef and artificial reef structures. This site is suitable for beginners, with depths ranging from 1 to 20 metres and an average depth of 10 metres. Divers experience mild currents and visibility between 8 and 20 metres. Marine life recorded here includes wrasses, porcupinefish, Titan triggerfish, and Bluespotted Fantail rays. Other species present are Pink Skunk anemonefish, Longfin bannerfish, and Blacktip grouper. Divers should be cautious of sharp edges on both the natural coral and artificial structures. Access is by boat, and dives typically last 45 minutes.

Tanote Bay, located on the east side of Koh Tao, offers a large reef area stretching along the coastline. The site features a mix of reef, artificial structures, and a sunken catamaran wreck located southeast of the prominent surface rocks. Depths range from 5m to 18m, with an average of 12m. Divers and snorkellers can encounter wrasses, blue-barred parrotfish, groupers, and porcupinefish. Other species include harlequin sweetlips, titan triggerfish, and the magnificent giant anemone. The site is suitable for beginners, though users should remain aware of boat traffic, surf, and sharp coral. Visibility varies significantly from 2m to 30m, and mild currents are typical.

Hin Wong Pinnacle is a reef and pinnacle site located near Koh Nang Yuan. The site offers depths ranging from 5 to 30 metres, with an average depth of 15 metres, making it suitable for beginners. Access is by boat only. Visibility is variable, ranging from 5 to 30 metres, and currents are generally mild but can strengthen. Water temperatures remain warm throughout the year, typically between 28 and 31 degrees Celsius. The site features a complex structure of rock and coral, which is also available for night diving. Divers should be aware of potential hazards including jellyfish, sharp coral, and fluctuating visibility.

Hin Wong Bay is a large, horseshoe-shaped bay located on the north-east coast of Koh Tao. This site features a diverse topography including reefs, caves, pinnacles, drop-offs, and artificial structures. Depths range from 2 to 40 metres, with an average of 18 metres. Divers and snorkellers can encounter species such as Blue-barred Parrotfish, wrasses, Rabbitfish, and hard corals. Less frequently, visitors may spot Harlequin Sweetlips, Titan Triggerfish, Golden Butterflyfish, Longfin Bannerfish, and Magnificent Giant Anemone. Conditions vary with visibility between 2 and 25 metres and mild currents. Thermoclines may occur, and hazards include boat traffic and sharp coral. Access is available via both shore and boat, with facilities including equipment rental and guided tours.

Lang Khaai Bay at Koh Nang Yuan provides a sheltered reef environment suitable for beginners. The site features a mix of hard and soft corals, alongside a cave and cavern system. Depths range from 5 to 23 metres with an average of 15 metres. Visibility typically spans 10 to 25 metres, supported by mild currents. Divers may access the site via shore or boat. Due to the presence of sharp coral and rocks, as well as overhead environments within the cave and cavern, careful buoyancy control is required. On-site parking is available for convenience.

The HTMS Sattakut is a 49-metre-long former navy vessel resting as an artificial reef near Koh Nang Yuan. The wreck lies at depths between 18 and 32 metres, with an average depth of 27 metres. Access is by boat only, as the site is located 800 metres from shore. Conditions vary, with visibility ranging from 2 to 30 metres and moderate currents. Divers should be aware of a potential thermocline at 25 metres, which can affect both temperature and visibility. Due to the depth and overhead environment, this site is suitable for advanced divers. Night diving is permitted at this location.