Aow Mao
Aow Mao (or Ao Mao) is one of the more secluded and tranquil dive sites on Koh Tao’s rugged east coast. Often overshadowed by the popular west-side sites, it offers a peaceful experience with a unique mix of natural reef and a relatively new artificial reef. In 2022, the site became even more significant with the sinking of the HTMS Hanhak Sattru wreck, making it a “two-for-one” dive that blends history with marine biodiversity.
Key Details
- Depth: 5 to 24 meters (The reef slopes to ~18m; the wreck sits upright in the sand at 20–24m).
- Skill Level: Open Water to Advanced. The shallow bay is perfect for training, while the wreck attracts those looking for more depth.
- Visibility: 10 to 20 meters. It is typically sheltered and calm during the Southwest monsoon (June–September).
- Topography: A gentle sandy slope punctuated by granite boulders and coral patches, leading out to the metallic silhouette of the 36-meter-long naval wreck.
Marine Life
- The HTMS Hanhak Sattru: Since its sinking, the wreck has quickly become a hub for life. You’ll often find large schools of Yellow tail Barracuda and Fusiliers swirling around the bridge. Look under the hull for Lionfish, Honeycomb Groupers, and the occasional Large Pharaoh Cuttlefish.
- Reef & Sandy Bottom: The surrounding reef is home to Blue-spotted Stingrays (often seen resting in the sand), Moray Eels tucked into rock crevices, and Scribbled Filefish.
- Macro Opportunities: Because the site is less trafficked, the macro life is thriving. Keep an eye out for Nudibranchs, Whip Coral Goby, and Pipefish along the rocky edges.
- Occasional Visitors: Though less common than at offshore pinnacles, Whale Sharks and Hawksbill Turtles are sometimes spotted passing through the bay.
Location
10.09284, 99.85246 Get Directions


