Must see
Abundant sea life
Sharks
Whale sharks
Koh Tachai is an island with several good dive sites, the most famous being Koh Tachai Plateau. Koh Tachai Island is situated 40km/25 mi south of Koh Surin Tai. It is one of the best sites for Thailand scuba liveaboards. It has a series of submerged pinnacles and boulders, which form excellent swim-throughs. The average depth is 20m/66ft and the maximum depth is 36m/118ft. Diving is best suitable for experienced divers
When To Go Diving
Diving season is from November to April. In the months of March and April, the visibility can drop to around 20-30m/66-98ft due to a higher density of plankton in the water. The water temperature is usually around 30C/86F at the surface and 27-28°C/81-82°F deeper down, but occasionally it can drop down to 25°C/77°F. March is the warmest month of the year with an average daytime temperature of around 34°C/93°F and January is the coolest month with the average temperature dropping down to as low as 22°C/72°F
What to see
The area also features numerous canyons and overhangs covered with large sea fans. The marine life is abundant and includes blue-dash, cube boxfish, giant batfish, trumpetfish, giant pufferfish, oceanic triggerfish, yellow-backed fusiliers, red-tooth triggerfish, big eye trevally, unicornfish, manta rays, whale sharks, leopard sharks, huge schools of swirling chevron barracuda and large numbers of tuna