White Rock Dive Site, Koh Tao: Depth, Map & Night Dive

White Rock, known in Thai as Hin Khao (also written Hin Kao), is one of the largest and most popular dive sites around Koh Tao. It sits about 2 km off the island's west coast, around 15 to 20 minutes by boat from Mae Haad and Sairee, and the name comes from the pale-looking northern pinnacle. If you want a White Rock dive on Koh Tao that works for almost every level, this is a safe bet.

The site is a sprawling reef with two big granite formations running south to north and a shallow coral garden between them. By day you get turtles, rays, morays and barracuda. After dark it turns into Koh Tao's classic night dive. It is big enough that you will want more than one dive to see it properly.

White Rock dive site map

2Northern pinnacle, top under 2 m
3Coral garden, sandy patch 9 m
4Southern pinnacle, to 22 m
5Southern buoy line, dive start

Usual route: Descend the southern buoy line, explore the deeper southern pinnacle, cross the coral garden and sandy patch, and finish on the shallow northern pinnacle. Drawing based on local dive briefings: approximate, not to scale and not for navigation. Your guide's briefing on the day always comes first.

Diving White Rock: the route

The usual plan is to drop down the buoy line at the southern end, explore the deeper southern pinnacle first, and then cross the coral garden and the sandy patch at about 9 m. You finish on the shallow northern pinnacle, where the rock tops come up almost to the surface and give you an easy safety stop.

Going from deep to shallow keeps the dive comfortable and gives you time at each stage. On a second dive you can reverse the order or spend your whole dive on one formation.

On a night dive the route is similar, but the deep-to-shallow order matters even more. Stay close to the rocks, where the hunting happens, and let your guide set the pace so you do not disturb the barracuda or startle the sleeping fish.

Underwater layout

Northern pinnacle: the pale-looking rock the site is named after. Its tops are less than 2 m below the surface and its base is at roughly 12 to 16 m.
Coral garden and sandy patch: between the two formations, at around 6 to 10 m.
Southern pinnacle: the deeper formation, sloping down to about 22 m, with crevices that hold shrimp and morays.
Southern buoy line: where most dives start.

The seabed around the rocks is sand and shale. The maximum depth is about 22 m, though some people quote a little more depending on where they measure.

The two formations are big enough that no two dives feel the same. The northern pinnacle is bright and busy with coral, while the southern one is darker and more rugged, with deeper cracks and ledges that repay a torch even in daytime.

Marine life at White Rock

By day you can see boulders and table corals, fan corals, Christmas tree worms, white-eyed moray eels and blue-spotted ribbontail rays under the ledges. Green turtles are regular, titan triggerfish patrol their patches, and yellowtail barracuda school near the southern buoy line. Angelfish, butterflyfish and bannerfish fill the reef, and whale sharks have occasionally been reported.

After dark the site changes. Great barracuda hunt in the beam of your torch, cuttlefish and squid appear, parrotfish sleep wedged in the coral, and turtles rest in crevices. Look for Durban dancing shrimp, cleaner shrimp, nudibranchs and juvenile reef fish on the macro side, and the odd octopus or banded sea krait.

The coral garden between the two pinnacles is worth a pause. Table corals and fans shelter small fish and shrimp, and it is a good place to look for rays resting in the sandy patch before you head up to the shallows.

Conditions and best time to dive

White Rock is mild to flat most of the year. Visibility is typically about 10 to 20 m and can reach 30 m on a very good day. The only real weather problem is the June to August monsoon, which brings wind and waves to this exposed west side. Most other months are a good time to go.

Tips from local divers

Start at the southern pinnacle and finish on the shallow northern one.
Turtles are easiest to find in the quieter parts of the day.
Barracuda hunting is most active at dusk and at night.
Look in crevices and under table coral, and plan more than one dive here.
Keep clear of titan triggerfish in breeding season.

Safety notes

Titan triggerfish can be aggressive in breeding season, so stay out of their patch and do not swim directly over a nest. On night dives, navigation in dark water takes concentration: stay close to your guide, check your torch and keep an eye on your depth and gas. White Rock is considered a boat dive, with the northern top under 2 m, but it is not a snorkelling site.