White Rock (Hin Khao) — Thailand

The Layout of White Rock

White Rock, or Hin Khao, consists of two distinct limestone pinnacles. These structures sit west of the main Koh Tao coastline. The depth ranges from 2 m at the top to 22 m on the base. I first visited this site in 2014 during a training course. It remains a staple for local dive centers.

Visibility typically stays between 10 m and 20 m. You will find the northwest side more sheltered. This area holds more macro life. The pinnacles rise sharply from the sandy bottom.

What you’ll see

Marine life here is quite specific. You can often spot a turtle grazing on the reef. Nudibranchs are common on the rock surfaces. I spent 45 minutes searching for them in 2018. They hide well in the crevices.

Night dives change the experience entirely. Divers go there to hunt for lionfish and octopus. The predators become active after sunset. It is a very different world at night. Many divers prefer this site for nocturnal spotting.

If you enjoy macro, stay close to the rock. The northwest side provides better opportunities. You might find small crustaceans there too. Small details require a steady hand.

Conditions and skill

This site is good for Open Water Divers. Most shops use it for checkout dives. The currents are usually mild here. This makes buoyancy control easier for students. You do not need advanced certifications yet.

However, the topography can be tricky. The pinnacles create small patches of surge. You must manage your depth carefully. If you struggle with buoyancy, stay near the bottom. Avoid the sharp edges of the rock.

Some days the surge feels stronger. This happens when the wind picks up. It is not a site for panicked divers. Practice your trim before attempting deep sections.

Logistics from Koh Tao

Most boats depart from Sairee Pier. The boat ride takes about 20 to 30 minutes. You can find many operators near Tanote Bay. Prices for a two-tank boat trip are roughly 1,100 THB. This is a standard rate for the region.

Check your gear before leaving the pier. You will need a good light for night dives. Many shops like Ban’s Diving or Sea Bees offer these trips. Always confirm the departure time in advance. Boats usually leave between 8:30 and 9:00 AM.

Bring your own surface marker buoy. Even with mild currents, visibility can drop quickly. A lost diver is hard to find here. Safety is your primary job.

When to go

The best months are March through September. During this window, the water is warmest. I prefer diving in May or June. The visibility often hits the 20 m mark then. You will see fewer crowds too.

Rainy season brings different challenges. The sea can get choppy in October. This affects boat stability and visibility. Still, you can dive most of the year. Just check the local weather reports first.

Avoid the peak December period if possible. The island gets very crowded then. You might share the pinnacle with 10 other divers. It ruins the macro hunting experience. Aim for the shoulder seasons instead.

Honest negatives

White Rock is not a remote site. You will see other boats frequently. The crowds can be quite large. This is a downside for solo photographers. It is hard to find a quiet spot.

Sometimes the visibility is poor. Silt can kick up from the bottom easily. This happens if divers hover too low. It makes macro spotting very difficult. You must keep your fins up.

Also, the pinnacle edges are sharp. You can easily scrape your tank or suit. Be mindful of your lateral movement. Avoid touching the reef at all costs.

Planning your visit

If you want to see octopus, book a night dive. If you want turtles, stick to the morning sessions. Check /destinations/koh-tao/ for more local info. You can also read about /dive-sites/gem-island/ for similar conditions.

Start with a shallow dive at Crystal Bay if you are nervous about currents. Then move to White Rock once you feel stable.