Phuket has some decent dive sites. Most dive sites are off nearby islands, but distances are fairly short and there are dozens of dive shops and boats to cater to your needs, most based near Chalong Bay. The reefs in the area are in a healthy condition with both solid hard corals and colourful soft corals. There is also an abundance of marine life. Most of the dive locations are suitable for all levels of divers, but there are also some that are quite deep.
The most well-known dive site in the Phuket area is Racha Yai with its sloping rocky reefs and its abundance of solid coral forests. It is home to Ter Bay where there is an exciting wreck in the depths of 25–35 m. The island south of Racha Yai, Racha Noi, is a haven for experienced divers as the depths are greater and the currents stronger. The overall topography is strikingly different from Racha Yai with huge granite boulders. The diving in Racha Noi compared to Racha Yai is definitely more challenging but the rewards are greater.
Just off Phuket, is the limestone island of Ko Doc Mai that soars vertically from the seabed. It is home to a diverse fish and offers the opportunity to view leopard sharks, moray eels, octopus, and turtles. Phuket can also function as a base for dives further afield, such as Ko Phi Phi. Diving in Phuket's warm clear blue waters is best from mid-Oct-May, when the calm seas and rain-free days make Phuket diving great.
Snuba Diving is the safest and easiest way to try diving on holiday in Phuket. The word Snuba is a portmanteau of "snorkel" and "scuba". The swimmer uses swim fins, a diving mask, weights, and diving regulator as in scuba diving. The air, however, instead of coming from tanks strapped to the diver's back, comes through a long hose from tanks on pontoon rafts on the surface. No certification required, children 8+, just like scuba diving except easier. Snuba trips go to most Phuket dive sites. No heavy equipment to wear, no long classes, maximum depth of 7 m. Professional dive guides accompany each group.