The Maldives have become famous as much for the marine life under the water, as they are for beach-life above. Thanks to their location far from the mainland, the waters around the islands are renowned for the abundance and variety of fish species. The lagoons include coral gardens and pinnacles teeming with schools of reef fish and other life, and deeper waters that are the haunts of zebra sharks, hammerheads manta rays, and whale sharks. The bright sunshine, clear water, and living colours are perfect for underwater photography.
Most resorts in the Maldives have a scuba diving facility and there are many specialist resorts offering dive training and advanced diving tours, as well as live-aboard boats that cruise among the archipelago's best dive sites for several weeks at a time. Scuba diving runs all year round, but the months from December to March have the best water visibility of up to 40 metres. Plankton blooms in the hottest months from April to June, attracting large pelagics such as manta rays and whale sharks. From June until August the Maldives have their wet season which reduces visibility and may restrict access to some dive sites.
The flow of the tides through the many atolls and islands of the Maldives creates significant currents, and so most boat dives here take the form of rapid drift-dives through the channels and lagoons formed by the corals reefs. These channels are filled with life and nutrients, and predators such as sharks and barracudas can often be seen cruising the currents and hunting nearby the divers, as well as sea turtles and giant Napoleon wrasse. Colourful frogfish lurk along the walls and caverns, and the reefs are home to many unique nudibranch species. Diving from the shore is also possible, and each resort has mapped out its nearby "house reef" for divers and snorkellers.
The atoll lagoons harbour many pinnacles of rock reaching almost to the surface, known locally as "Thilas". Water from the ocean floor rises along the slopes of the thilas, and they are crowned with hard and soft corals, sponges and fans. Many thilas also serve as cleaning stations for larger animals like manta rays who may circle slowly nearby attended by schools of cleaner wrasse.
Ari Atoll is the second-largest atoll in the Maldives, and is considered one of the best for diving. Resorts on the islands of the atoll will be able to reach many of the major dive sites here in a half-day boat trip, and can organise longer trips to the further sites. Ari has several thilas known as good spots to see mantas, and sites such as Maamigili and Gangehi Maavaru, where whale sharks are seen in season. Rasdhoo Atoll to the north-east of Ari is famous for its school of hammerhead sharks.
Because of the strong currents, divers in the Maldives must pay close attention to their depth at all times. All dive operators require the use of dive computers, and most will offer them for hire. Divers also need to carry and know how to use a signal-marker buoy to summon the dive boat at the end of their drift dive. There are hyperbaric chambers are located on North Male atoll and Rasdhoo Atoll. Nitrox is rarely available.