The water temperature provides ideal conditions for coral, shells and fish which all thrive. The lagoon is home for an amazing array of exotic fish and sea-life. Marine reserves around New Caledonia protect the underwater eco-system and the sunken wrecks which act as artificial reefs make great diving spots.
New Caledonia has the world's second biggest coral reef and is located in the Coral Sea where also Australia's Great Barrier Reef lies. The diving and snorkelling are just as spectacular too. Underwater visibility in New Caledonia's reef is as long as 50m (165ft), but that is in optimum conditions, i.e., with calm seas, no wind, and in winter. Summer is the rainy season, so the water can loose some visibility from water runoff originating on land.
Bay of Prony
On the southern end of the main island is the Bay of Prony which has underwater hydrothermal activity . There are enormous stalagmites including 'The Needle of Prony', which reaches 38 metres high, but can be seen at 1.5 metres (4.9 feet) under the water. It has all kinds of sealife clinging to it and is well worth a look.
20 kms south of Noumea the Amedee lighthouse marks an entrance through the barrier reef. This area abounds with great underwater sights. It's a marine reserve where you can see Manta Rays and sharks in the pass or explore the wreck of the Dieppoise, sunk in 1988, which has become a haven for many species including groupers, parrotfish, trumpet fish and trevalli. Nearby are the Abore, Sounois, and Tabou reefs, where fish life abounds including turtles and barracudas. For exquisite coral formations dive the Grotto and Forest of the Snark.
The town of Hienghene on the east coast of Grande Terre the main island, has diving with visibility up to an beyond 30 metres. There are caves and tunnels here, as well as colourful coral gardens.
Tenia is located 100 kms (62 mi) north of Noumea and on the outer reef. This area has coral gardens, rich sealife, and dolphins.
The Isle of Pines has numerous spots with crystal clear water and colourful coral gardens. Satan's Cave for example, has fresh water which can reached by a narrow via an underwater corridor.