2. Rangiroa, Polynesia

Few places have captured my imagination like Polynesia, and the beautiful islands of the Tuamotu Archipelago about 250 miles from Tahiti felt incredibly remote. Rangiroa means "Long Sky" and it is the second largest atoll in the world. Two passes, or channels, named Tiputa and Avatoru, allow the Pacific into and out of the lagoon twice daily when the tides turn. I remember being carried through by the incoming tide and sharing the ride with scores of grey reef sharks, dolphins, mantas and sometimes large hammerhead sharks, too. It is high adrenalin diving, but above water, the atoll is one of the most laidback places in the world.
 

Dive details: Dive with The Six Passengersand stay in a locally run pension such as the Tuanakefor around £50pp a night.