1 · Koh Tao · Boat access
Japanese Gardens, Koh Nang Yuan
Visibility 10–25 m2–3 m deep250 THB entryAll levels
The consensus number one snorkel site in the whole region, on the east side of the sandbar connecting Koh Nang Yuan's islets just off Koh Tao's northwest coast. Named for coral bommies arranged like a manicured garden across a sandy seabed, it is shallow — roughly 2–3 m sloping to 10–12 m — sheltered, with little current. Multiple dive schools describe it as one of the most biodiverse coral areas of its size in Thailand: parrotfish, butterflyfish, angelfish, clownfish in anemones, occasional blacktip sharks and turtles.
Suitability: excellent for all levels, including families and first-timers. Access: boat only — longtail from Sairee or Mae Haad at roughly 250–300 THB round trip, or on a snorkel tour. Koh Nang Yuan charges a 250 THB entrance fee, and fins and plastic bottles are banned on the island to protect the coral; bags are checked. Best time: arrive before midday to beat the tour crowds; dry season, roughly February to May, for the clearest water.
Caveat: the shallow water near the main beach is heavily trafficked and the coral there is worn. The best coral is 100–200 m out toward the buoy line. Some reviewers describe the coral bed near shore as "badly damaged."
2 · Koh Tao · Shore or boat
Hin Wong Bay
Richest reef~50 THB parkingConfident swimmers
Frequently rated by locals as Koh Tao's single best snorkel bay for coral and fish density. On the quieter east coast, ringed by granite boulders. Some of the healthiest table, brain and boulder corals on the island grow on the rock faces — the sandy-seabed corals have largely died — with big schools of fusiliers, parrotfish, butterflyfish, rabbitfish, blue-spotted stingrays and occasional blacktip sharks.
Suitability: better for confident swimmers. The best reef is a 20–40 m swim out and along a rocky shoreline, and boat traffic can be heavy when dive boats shelter here on windy days — not ideal as a shore snorkel for weak swimmers. Best time: early morning for calm water, fewer boats and the fusilier schools. Access: a steep sealed road by scooter with about 50 THB parking, or by boat tour; the small private beach asks you to buy something to use its facilities.
3 · Koh Tao · Shore access
Aow Leuk
Baby blacktips50–100 THB entryBeginners
The best beginner and shore-entry snorkel on Koh Tao, and by several accounts "the best snorkelling on Koh Tao" for sheer accessibility. A deep, concave bay on the southeast coast with a gentle sandy entry, calm water even at low tide, and coral on both rocky sides. Its signature draw is baby blacktip reef sharks in very shallow water — often visible in water you can still stand in, best in late afternoon.
Suitability: ideal for beginners, families and nervous swimmers. Best time: late afternoon for the baby sharks, on calm days. Access: easy paved road by scooter; entrance fee reported at 50–100 THB, which includes a lounger or a soft drink, with gear rental on the beach. Caveat: the beach itself is not always the cleanest and the near-shore coral is unremarkable — the better reef is toward the northern rocks.
4 · Koh Tao · Shore access
Tanote Bay
FreeCoral close inAll levels
An underrated all-rounder: easy shore access with no long hike or boat needed, healthy coral starting close to shore around a large central boulder — also a cliff-jumping spot — and a big variety of reef fish including large schools of yellow snapper and barracuda. Consistently described as having some of the healthiest coral reefs and marine life on Koh Tao.
Suitability: all levels, and genuinely good for families. Best time: morning, for calm water. Access: free; 15–20 minutes by scooter from Mae Haad or Sairee on a new sealed road.
5 · Koh Tao · Shore or boat
Shark Bay (Thian Og Bay)
Green turtles daily200–500 THB entryIntermediate
The most reliable place in the region to snorkel with green sea turtles, with daily sightings at 5–7 m depth, plus a chance at adult and juvenile blacktip reef sharks. It sits on the southeast tip.
Reality check: despite the name, sharks are not the main event — Aow Leuk is better for those — and the coral is mostly dead, damaged by the 1998 El Niño and never fully recovered, so fish diversity is lower than at Tanote or Hin Wong. Suitability: intermediate; the turtles are roughly 150–250 m out and it is a big bay with potential currents. Best time: early morning or late afternoon for turtles and sharks. Access: the primary land route is through Haad Tien Beach Resort, which now charges a fee — reported at 200–500 THB depending on source and year, and while a technically free path exists, resort staff increasingly request payment. Also reachable by boat or kayak.