Koh Haa Lagoon

"Koh" means "island," and "Haa" means "five." Confusingly, however, Koh Haa consists of six limestone islands located west of Koh Lanta.

Koh Haa Lagoon is an enchanting place. Tall, rugged limestone cliffs—some covered in greenery—and the turquoise-blue waters of the lagoon make this spot the epitome of a vacation getaway. The lagoon is approximately 3–8 meters deep, with two additional small reefs located just offshore. You can easily explore the lagoon and these two reefs in a single dive without having to rush.

Toward the two reefs, the sandy bottom slopes slowly but steadily down to 30 meters. The reef walls are beautifully covered in marine life, and divers who love nudibranchs, wart snails, ghost pipefish, anglerfish, and more will be in for a real treat here. It’s also worth looking out into the open water—large tuna and rainbow trevally often swim by here. Between the two reefs lies a large field of antler coral, where you can find moray eels or small sea snakes.

Excellent light conditions, schools of sergeant major fish, reef squid, cuttlefish, and octopuses hiding in small coral blocks make the shallow lagoon the perfect spot for a safety stop and to decompress. But be careful: It’s advisable to do your safety stop here using a current buoy. Not because the current is so strong, but because the lagoon is used as an anchorage by many boats, and longtail boats in Thailand have propellers that extend very deep into the water.