Koh Chi is the small and northernmost island of the five which make up the Surin Islands. It is a small and interesting dive site but sometimes al little challenging. Koh Chi is slightly exposed, but still offers some protection. Its exposed location allow for cleaner water and more interesting marine life to be attracted to it. Sightings of the 'big two' - Manta Rays (Manta birostris) and Whale Sharks (Rhincodon typus) – are unlikely, but these huge filter feeders are all around these waters, so it's always worth keeping an eye out into the blue.
The dive site consists of a sloping reef away from the islet, and there are dozens of granite boulders scattered around on the sea bed to the north. Mainly hard coral, but some soft and sea fans, have made roots here and given shelter and food to all kinds of fish and invertebrates.
There are some predatory larger fish, such as Giant Trevally (Caranx ignobilis), Barracuda (Sphyraena) and even tuna who school around nearby in the hope of a snack. There is also the possibility of coming across a turtle or even a sea snake here. Those really fortunate and observant will see a Ribbon Eel (Rhinomuraena quaesita) which is an amazing fish.
Diving depths here average at about 18 metres and max out at just over 20 metres. Down at the bottom it is sometimes possible to see a Whitetip Reef Shark (Triaenodon obesus) resting for the day.