Koh Samui Dive Sites

Sail Rock

Sail Rock is one of the best dive sites in the area. It’s a big granite pinnacle that breaks the surface half way between Koh Pha Ngan and Koh Samui and as there are no other rocks around it acts as a congregation point for all the fish in the surrounding area.

The pinnacle drops down to 30 metres in the sand and is typically dived in a circular route around the rock, spiraling slowly shallower. If currents are strong however, divemasters will guide customers around the sheltered areas, avoiding hard finning in the currents. There are other outer rocks a little deeper that can be seen from the main pinnacle and are home to reef sharks.

On a clear day, with light filtering down into the crystal blue water, the granite boulder looks stunning. Enormous schools of trevally are all over the dive site and they energetically harass the smaller fish which bunch together and move as one for protection from these darting raids.

The always friendly longfin batfish are also often present in great numbers. They may follow divers and curiously peer into your mask, seemingly as interested in you as you are in them. They make wonderful photographic subjects. Whale sharks occasionally cruise by too as do other pelagic fish. Always keep one eye on the big blue!

Sail Rock is best known for its chimney, a large swim-through that is entered at around 20 metres and can be exited in two places, first at around 10 metres or shallower at around 5 metres deep. The chimney’s cavern-like area is a haven for all sorts of fish life like schools of glassfish that appear to block your exit, only to part at the last second to reveal the holes.

Hingebeak and boxer shrimps inhabit the coral wall. The latter can sometimes be seen cleaning a moray eel's teeth and, with patience, a lucky diver could get a free manicure if they leave their hand still for long enough. Scorpionfish are well camouflaged on the wall so care with buoyancy is required when exiting the chimney. The hole at 10 metres is quite tight so most divers carry on up to the 5 metre exit and are rewarded by a blanket of anemones on the outer side.

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Sail Rock Reef Basics: Great for big schools of friendly batfish and trevally
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: Beginner - advanced
Number of dive sites: 1
Diving Season: All year round
Distance: About 75 km from Samui (1½ hours by speedboat), or 25 km from Koh Tao
Access: Day trips from Koh Samui

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