Must see
Koh Bida Islands
Koh Bida Nai is a small island, located 2km south of Koh Phi Phi Ley. This site features walls, caves, boulders and fallen rocks that create some interesting swimthroughs hidden behind large shoals of glassfish. Divers can choose to explore Fantasy reef, located on the south-east side of the island (18-27m/59-88ft deep) or visit another shallow sloping reef on the east side, ideal for novice divers (depth 12m/39ft). Good buoyancy control is important as bearded lionfish are lurking on the bottom.
When To Go Diving
The best time to dive is from November to May, though diving is possible all year round. The air temperature ranges from 25C/77F to 32C/90F and water temperature is about 29C/84F all year round.
What to see
Some areas on the west side of the island and on the north and north-east side feature lots of small reef fish, including many nudibranchs, seahorses, ghost pipefish, shrimp and other species. Various schools of large predator fish, like blacktip reef sharks and leopard sharks, barracudas and trevallies can be seen hunting near the reef wall. Varying sizes and species of colorful parrotfish and wrasse, along with large shoals of moorish Idols are expected to be seen to be at all depths. Also divers can explore many gorgonian sea fans, whip corals and colorful soft corals.