Koh Samui Island Diving

Sail Rock

Sail Rock is a large granite pinnacle that breaks the sea's surface, half way between Koh Pha Ngan and Koh Samui. It's the best dive site in the Gulf of Thailand. There are no other rocks nearby so it acts as a congregation point for all fishes in the surrounding area.

The pinnacle rises from the sandy bottom at 30 metres and is typically dived by looping around the rock, spiralling ever shallower.If currents are strong then divemasters will guide divers around to the sheltered areas, avoiding the need for hard kicking into the current.

On a sunny day when the light filters down into the aquamarine waters, the granite boulder looks stunning. Huge schools of trevallies roam all over Sail Rock and energetically hunt the smaller fish that bunch together for protection from these darting raids. There are several more rocks a little deeper that can be seen from the main pinnacle and these are home to reef sharks.

Longfin batfish may also be present in great numbers and they make wonderful photographic subjects. They often follow Samui divers, curiously peering into your mask, as seemingly interested in you as you are in them. Between Februray and October, whale sharks occasionally cruise by. As do other pelagic fish so always keep an eye on the big blue!

Sail Rock's best known feature is its chimney - a large swim-through that is entered at around 20 metres and can be exited in 2 places, first at 10m or shallower at 5m deep. The chimney's cavern-like area is a haven for all sorts of fish life such as schools of glassfish that block your exit path, only to part as you approach to reveal the holes.

Hingebeak and boxer shrimps inhabit Sail Rock's coral wall. The latter can sometimes be seen cleaning moray eel teeth and, with a little patience, a lucky diver might get a free manicure if they leave their hand still for long enough and allow the shrimp to gently clean their cuticles. Venomous scorpionfish are well camouflaged on the wall so care with buoyancy control is required to exit the chimney. The hole at 10 metres is quite small so most divers carry on up to the 5 metre exit and are rewarded with a carpet of anemones on the outer wall side.

Sail Rock Reef Basics: Whale sharks and big schools of fish
Depth: 5 - 30m
Visibility: 10 - 30m
Currents: Can be strong
Surface conditions: Normally calm, but can get choppy
Water temperature: 27 - 29°C
Experience level: Intermediate - advanced
Number of dive sites: 1
Diving season: All year round
Distance: About 30 km from Samui (45 minutes by speedboat), or 50 km from Koh Tao
Access: Scuba diving day trips

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