Bida Nok
Overview
Bida Nok is a small limestone island rising sharply from the Andaman Sea approximately two kilometres south of the main Phi Phi island group. Its sheer underwater walls, carpeted in sea fans and soft corals, make it one of the most visually striking dive sites in southern Thailand. The island's submerged cliffs drop from the surface to 28 metres where they meet a sandy slope scattered with coral bommies. The site is best known for its reliable leopard shark encounters. These docile bottom-dwellers rest on sandy ledges along the southern and eastern faces, typically at depths of 18 to 24 metres. During high season it is common to find three or four individuals on a single dive, lying motionless on the sand and allowing patient divers to observe them closely. Blacktip reef sharks also patrol the deeper sections, while banded sea kraits hunt through the reef crevices. The western wall is the site's visual centrepiece, covered in enormous purple and red sea fans that extend from the wall face like living parasols. Between the fans, dense clusters of soft corals in yellow, pink, and white create a colourful mosaic. Several swim-throughs cut through the limestone at various depths, their interiors filled with glassfish that shimmer in torch beams. Moray eels peer from holes along the wall, and octopuses change colour against the rock surface. The shallow reef on the northern side provides excellent conditions for safety stops and extended bottom time. Hard coral coverage here is impressive, with table corals, staghorn thickets, and brain corals supporting clouds of anthias and damselfish. Hawksbill turtles graze on the reef flat, and the nooks between corals hide nudibranchs, porcelain crabs, and ornate ghost pipefish that delight macro photographers. Morning visits offer the calmest seas and best visibility.
Marine life
Dive profile
DEPTH PROFILE
DEPTH PROGRESSION & WAYPOINTS: Bida Nok
Location
Frequently asked questions
Are leopard shark sightings common at Bida Nok?
Leopard shark sightings at Bida Nok are remarkably consistent during high season between November and April. Multiple individuals are often found resting on sandy patches at depths of 18 to 24 metres along the southern side of the island. They are docile bottom-dwelling sharks that allow careful divers to approach within a few metres for photographs. During low season sightings become less frequent due to reduced visibility and shifting currents, though they do not disappear entirely from the area.
What is the best way to explore Bida Nok?
Most dive operators run a circuit around the island starting from the mooring on the sheltered eastern side. Divers descend along the wall heading south to find leopard sharks on the sandy slopes, then round the southern tip where currents bring nutrient-rich water supporting dense soft coral growth. The western wall features the best sea fan coverage and several swim-throughs. The dive typically finishes on the shallow reef flat on the north side at five to eight metres depth, an excellent area for safety stops with abundant hard corals and macro life including nudibranchs and mantis shrimps.
Reviews
Reviews
No reviews yet
Data Provenance
This profile is compiled from 3 operator submissions and 142 community logs. Key facts (depth, entry) are verified against official hydrographic charts.