Sai Daeng Beach is a shore-access reef site located on Koh Nang Yuan, Thailand. The site features a shallow average depth of 4 metres, ranging between 2 and 6 metres, making it suitable for beginners and snorkellers. Divers and snorkellers can observe a variety of marine life, including common sightings of Titan Triggerfish, wrasses, Longfin Bannerfish, Golden Butterflyfish, and Blue-barred Parrotfish. Uncommon species recorded here include Bluespotted Fantail Ray, Blue Ringed Angelfish, Pink Skunk Anemonefish, and Blacktip Grouper. The site offers visibility between 10 and 30 metres with mild currents, though users should remain aware of potential strong currents. Facilities include parking, toilets, equipment rental, and a cafe.

Shark Island is a surface-breaking pinnacle located 300 metres off the southern tip of Koh Tao. This site features a mix of reef, drift, and artificial reef topography, descending to a maximum depth of 28 metres with an average of 14 metres. Due to its location, the site experiences strong currents and variable visibility ranging from 3 to 30 metres. Divers and snorkellers may encounter wrasses, golden butterflyfish, and blue-barred parrotfish, alongside less frequent sightings of bluespotted fantail rays, titan triggerfish, and harlequin sweetlips. Access is by boat only. Hazards include strong currents, down currents, and sharp coral. Thermoclines can occasionally reduce water temperatures from the typical 28 to 31 degrees Celsius down to 24 to 25 degrees Celsius.

Hin Ngam, located off Koh Nang Yuan, features three distinct pinnacles set against a sandy seabed. This site offers a mix of coastal reef exploration and navigation between scattered pinnacles, with depths ranging from 5 to 18 metres. Divers and snorkellers frequently encounter Titan Triggerfish, wrasses, Longfin Bannerfish, Golden Butterflyfish, and Blue-barred Parrotfish. Other species present include Bluespotted Fantail Rays, Blue Ringed Angelfish, Harlequin Sweetlips, Scrawled Filefish, and Pink Skunk Anemonefish. Conditions are generally mild with visibility between 10 and 25 metres. Hazards include boat traffic, sharp coral, and the presence of triggerfish and stonefish. The site is accessible by boat or from the shore and is suitable for beginners.

Shark Bay at Koh Nang Yuan is a shallow reef and seagrass site suitable for both diving and snorkelling. The site features depths ranging from 3 to 8 metres, with an average depth of 5 metres. Access is via the shore, and conditions are generally mild, though visibility can fluctuate between 5 and 30 metres. The area is well-suited for beginners and supports night diving. Facilities available at the location include parking, toilets, and a cafe. Divers and snorkellers should remain aware of potential hazards, including boat traffic, jellyfish, and sharp coral.

Aow Leuk is a wide, shallow bay located on the east side of Koh Tao. The site features a sandy bottom, natural coral reefs, and artificial reef projects consisting of concrete block sculptures. Divers and snorkellers can explore depths ranging from 5 to 15 metres, with an average depth of 8 metres. The site is suitable for beginners and accessible by both boat and shore. Visibility typically ranges from 5 to 20 metres, and currents are generally mild. Facilities available at the site include a cafe, restaurant, toilets, equipment rental, and accommodation. Night diving is permitted, with typical dives lasting 45 minutes.

Freedom Beach is a shallow reef located at the southern tip of Koh Nang Yuan. Divers and snorkellers can access this site directly from the shore. The reef, situated near Buddha Rock, reaches depths between 2 and 14 metres with an average of 7 metres. Conditions are generally mild, though visibility fluctuates between 5 and 20 metres. Marine life frequently observed includes Titan Triggerfish, Longfin Bannerfish, Golden Butterflyfish, and Blue-barred Parrotfish. Divers may also encounter Bluespotted Fantail Rays, Blue Ringed Angelfish, and various wrasses. Hazards at this site include jellyfish, sharks, and sharp coral. Facilities available include toilets, showers, and gear storage.

Buddha Rock, located off Koh Nang Yuan, is a reef site suitable for both snorkellers and beginner divers. The site features depths ranging from 1 to 14 metres with an average of 10 metres and visibility between 10 and 30 metres. Divers and snorkellers frequently encounter wrasses, longfin bannerfish, golden butterflyfish, and blue-barred parrotfish. Less common sightings include bluespotted fantail rays, titan triggerfish, pink skunk anemonefish, and various groupers. The site is accessible by boat or from the shore. Visitors should remain aware of boat traffic and the presence of sharks. Night diving is available through local dive shops, offering a different perspective of the reef.

King Kong Rock is a reef and artificial reef site located 500 metres off the coast of Koh Nang Yuan. The site features depths ranging from 5 to 30 metres, with an average depth of 14 metres. Access is exclusively by boat, and the site is suited for intermediate divers. Conditions typically include mild currents and visibility between 10 and 25 metres. Water temperatures remain warm throughout the year, ranging from 28 to 31 degrees Celsius. Divers should be aware of potential hazards, including jellyfish and stonefish. A typical dive at this location lasts approximately 45 minutes.