Bucket lists are for landlubbers. If you're a diver, and the ocean is your oyster, then you NEED to dive these spots, arguably the greatest dive sites on our blue planet.

Roca Partida, Revillagigedo Islands, Mexico

Roca Partida is an eroded rock resembling a whale's tail rising from the deep Pacific, off of the Mexican coast. Beneath the waves you're seemingly alone in the big blue until silky, Galapagos and hammerhead sharks surround you, sometimes in their hundreds.

Fujikawa Maru, Chuuk Lagoon, Micronesia

Japanese aircraft transport ship Fujikawa Maru was one of 61 ships sunk by the American air force in February 1944 and is one of the world's greatest wreck dives. The Bow is dominated by a huge gun and the six holds contain torpedo and artillery shells, gas masks and - in Hold Two - an almost intact Mitsubishi A5M 'Claude' airplane, and a number of Mitsubishi A6M 'Zero' cockpits.

Shark Hole, Tikehau, French Polynesia

Jacques Cousteau described Tikehau Atoll as richer in marine life than any lagoon in the world, and Shark Hole, near the Tuheiva Pass out into the open ocean, is the ultimate dive site. Expect 100ft visibility, inquisitive grey reef sharks, thousands of squirrelfish, hawksbill turtles and a spectacular coral garden as a finale.

Mapinduzi, Pemba Island, Tanzania

A boat trip away from Fundu Lagoon on Pemba, Mapinduzi is a 100ft wall dive overlooking a deeper abyss where you drift along on the incoming tide spotting hammerheads, shoals of giant barracuda and eagle rays.

Cod Hole, Great Barrier Reef, Australia

The Great Barrier Reef is home to the iconic Cod Hole, where enormous (and enormously greedy) potato cod swim around you waiting to be fed by the dive guide. Keep an eye out for clownfish, Napoleon wrasse and bumphead parrotfish as well.

Neptune’s Arm, Vamizi Island, Mozambique

Several expert divers with several thousand dives under their weight belts consider Neptune's Arm to be the crème de la crème of dives, and with good reason - it's got everything from jaw-dropping geography to an abundance of marine life both big (grey reef sharks galore and groupers the size of Minis) and small, and near perfect visibility when conditions are right.

Tiputa Pass, Rangiroa, French Polynesia

The tidal Tiputa Pass flows from open ocean into the Rangiroa lagoon, funneling vast numbers of fish and larger predators through a narrow gap in the reef. Marine biologists have counted as many as 1500 grey and hammerhead sharks around the mouths of the pass at one time. This may not sound like the best place for a snorkel, but with visibility often up to 40 metres, snorkellers can also get in on the action. Even better this is pretty much effort free, as you plop off the side of the boat and, taken by the strong current, you join the marine migration drifting along above sharks, dolphins, manta rays and thousands of colourful reef fish.

Cape Kri, Raja Ampat, Indonesia

Raja Ampat is the epicentre of the Coral Triangle, the part of the Pacific Ocean between Indonesia, Malaysia, the Philippines, Papua New Guinea and the Solomon Islands. The diving here is generally considered to be the best in the world, and at Cape Kri esteemed marine biologist Dr Allen counted an astonishing 374 different species of fish. Think giant schools of tuna, trevally, fusiliers, snappers and surgeonfish, then throw in some sharks, barracuda, a few turtles, some aesthetically-challenged bumphead parrotfish and much, much more. Believe the hype, it is THAT good.