Koh Racha Noi is defined by strong currents, varied topography and an impressive spread of site types. Reef, wall, pinnacle, drift and cavern dives are all represented, from shallow bays suited to beginners through to deep-water pinnacles that demand advanced certification. The Giant Moray, Titan Triggerfish, Indian Lionfish and Peacock Mantis Shrimp are observed consistently across sites, while the Whale Shark is among the signature species. All sites are boat access only.
Monthly water temperature across Koh Racha Noi's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water temperature stays warm throughout the year, with the coolest readings in February and March and a slight peak through the middle months. The best-months data points clearly to November through April as the favoured window, aligning with calmer, clearer conditions. From May to October, stronger seasonal weather reduces visibility and makes the more exposed sites, particularly those at the tips and northern end, considerably more demanding.
1 operator
Thailand
6 more sites to explore
Water temperature around Koh Racha Noi ranges from about 28°C in February to 30°C in April, based on satellite sea-temperature data for its dive sites.
With water around 28–30°C, a rash guard or 3mm shorty works in Koh Racha Noi year-round.
Fin maps 18 sites in Koh Racha Noi (18 scuba diving sites and 3 snorkelling spots, with some suited to both).
Across Koh Racha Noi's dive sites, January, February, March, April, November and December are most often reported as the best months to visit.
Observations across the sites show the Giant Moray, Indian Lionfish, Titan Triggerfish, Reef Stonefish and Peacock Mantis Shrimp as consistently present. The Pharaoh Cuttlefish, Coral Grouper, Yellow Boxfish and Moorish Idol are also regularly recorded. The Whale Shark is listed among the island's signature species, though sightings are less predictable.
Several sites, including Manta Bay, Banana Bay, Camera Bay and Racha Noi Bay, are rated for beginners and offer shallower reef and wall sections. However, a significant number of sites carry intermediate or advanced ratings due to strong currents and deep topography. Beginners should confirm site conditions with their operator before heading out.
The island offers considerable variety. The northern and southern tips are current-driven drift dives with pinnacles and drop-offs that suit experienced divers. Sites like Manta Bay and Racha Noi Bay combine reef, wall and artificial structures in shallower water. Marina Bay and Marita's Rock add granite formations and cavern sections, while The Rock is a deep-water pinnacle reserved for advanced divers.
Every dive site at Koh Racha Noi is accessed by boat. There are no shore-entry sites listed for the island. Divers should arrange passage through a dive operator based in Phuket, as no operators are currently listed as operating directly from the island.
