Koh Doc Mai

Koh Doc Mai is not far from Chalong bay and is a little limestone island with limestone cliffs rising out of the water and underwater cliffs droping to 25-30m. It is a wall dive often with a current that can make it a great drift dive. There is much to see tucked in the cracks along the wall from bamboo Sharks to Ornate Ghost Pipe-fish and Seahorse. KDM also has one of the best selection of Nudibranks.

But when diving the wall do keep an eye out into the blue as Whale Sharks and other larger marine life can often pass by without being noticed. There are also several caverns on KDM for those qualified who have the right equipment and training.


Often used as a dive site on the way to/from the King Cruiser Wreck, Shark Point or Phi Phi, it’s considered the best wall dive in the area. The larger east face and smaller north / south ends offer steep walls covered in small colorful corals that are just teaming with macro marine life, where as the west side offers a sloping / ledges of hard coral reef.

The base of the island meets the sloping bottom at depths of between 18-22m, where the bottom continues out to 30m and 40m in  some places. Predominantly a sandy-rubble base on the east, north and south and a soft sandy base with large soft coral covered boulders on the west, this dive site can be prone to strong currents (great for drift diving) and very varied visibility – on a good day it can be stunning, particularly in the current – on a bad day, maybe 3-5m visibility.

Koh Doc Mai is well suited for experienced divers who want to see something special or for those on more advanced courses or drift diving courses.

Dive Boats Day Trips

For qualified divers only
If you are not qualified and want to try diving go here

Racha Yai

2 Dives
Racha Yai Only
Every Day
Return by 15:30
3,500 Baht

Racha Yai / Noi

3 Dives
Racha Yai + Racha Noi
Most Days
(except Tue & Sun)
3,800 Baht

Phi Phi

3 Dives
Phi Phi + either
Every Day
3,800 Baht