Marina Bay/Marita’s Rock

Marina Bay, also known as Marita's Rock, is an advanced dive site at Racha Noi island that plunges to an impressive forty meters, making it one of the deepest recreational dive sites in the Phuket day-trip range. This dramatic site on the island's western coast combines deep wall diving, pelagic potential, and spectacular underwater scenery in a package that challenges and rewards the most experienced divers. The underwater terrain at Marina Bay features massive granite formations that drop steeply into deep water. The forty-meter depth is accessible along the deeper edges of these formations, where the rock meets the sandy bottom in an area where pelagic species are most likely to be encountered. The scale of the rock formations is impressive, with boulders and walls creating an underwater landscape of dramatic proportions. Manta rays are a genuine possibility at this deep, exposed site. The current that flows around the western coast of Racha Noi brings the plankton concentrations that attract mantas, and the deeper water provides the space these large animals prefer. Encounters at forty meters in crystal-clear Andaman water, with the granite wall as a backdrop, create some of the most powerful diving moments available anywhere in the Phuket region. The reef community adapts to the depth gradient, with hard corals dominating the shallower zones and soft corals, sea fans, and sponges taking over as depth increases and light diminishes. The deeper sections host organisms adapted to reduced light, creating biological interest even at the maximum depth. Fish schools are impressive, with trevally, barracuda, and fusiliers orbiting the formations. The forty-meter depth demands serious dive planning. Gas management, narcosis awareness, and strict adherence to decompression protocols are essential. Many experienced divers choose enriched air to optimize their bottom time and safety margins. The current exposure adds another layer of challenge, and the site should only be attempted by divers with solid deep diving experience. Marina Bay at Racha Noi represents the extreme end of Phuket-area recreational diving. The combination of impressive depth, dramatic topography, and genuine pelagic potential creates a dive that pushes boundaries while delivering experiences of rare intensity and beauty.