Divers, with their leisurely frog kick and rhythmic zen breathing, are often excluded from extreme sports. Yet, if exploring new realms gets your blood pumping, few sports can compete with diving. For seasoned divers wanting to take it up a notch, the ocean is rife with adrenaline-packed adventures. From thrilling drift dives to shark frenzies to diving in the pitch black open ocean, read on to discover the world's best adrenaline diving.

School of reef sharks in French Polynesia

Fakarava and Rangiroa, French Polynesia

The best way to boost your adrenaline? Thousands of groupers, hundreds of sharks and one mass feeding frenzy. Located in French Polynesia's Tuamotu Islands, Fakarava is a UNESCO Biosphere Reserve and the jewel in French Polynesia's diving crown. Every year, between June and July, tens of thousands of marbled groupers gather in South Fakarava to spawn - and where there's groupers, there's sharks. Dive just before sunset to see hundreds of grey reef sharks attack in a blink-and-you'll-miss-it mass feeding frenzy.

Further north, Rangiroa, the largest atoll in the Tuamotu Islands, boasts another of the world's best adrenaline dives. Tiputa Pass, a narrow strait linking Rangiroa lagoon to the open ocean, propels divers in ripping currents alongside bottlenose dolphins, whitetip sharks, black tip sharks, grey reef sharks, silkies, schools of eagle rays and great hammerheads (November to February).

Scuba diver in a dry suit at Silfra, Iceland

Iceland

Iceland, home to some of the best cold water diving on the planet, isn't for the faint hearted. While Silfra, the glacial water-filled fissure separating the North American and Eurasian tectonic plates, is the main draw for divers, a plethora of lesser-known adrenaline-packed dives exist. Tucked between Norway and Greenland in the chilly North Atlantic Ocean, divers can take their pick of inland and ocean sites, ranging from the deep, eerie SS El Grillo WWII wreck (look out for wolffish) to toasty, bubbling hydrothermal chimneys - all in two-degree water.

Manta ray swimming in front of a light at the bottom of the ocean

Kona, Hawaii

Blackwater diving offers the world's best adrenaline diving for those who get a kick from the deep dark open ocean. Unlike night diving, where divers cruise a reef with a torch, blackwater diving involves being tethered miles offshore. Blackwater diving originated in Hawaii's Big Island, also known as Kona, and this wild island remains one of the best places to see pelagics of the deep. Here, floodlights are lowered below the boat to attract the translucent, bioluminescent creatures of the deep, ranging from larval octopuses and shrimp to jellyfish. For those not ready to venture into daylight, closer to shore, Kona's manta ray night dive is one of the most exhilarating dives on the planet.

Divers interacting with a Tiger Shark

Tiger Beach, Bahamas

Alongside bull sharks and great whites, tiger sharks are the 'Big Three' deadliest sharks in the world. Despite their reputation as the ocean's most feared predator, there is a place where you can dive with these misunderstood creatures in a safe setting. The Bahamas is a protected shark sanctuary, which has enabled shark populations to thrive - with Tiger Beach being the best place in the world to dive with tiger sharks. The sharks here are fed, which reduces their interest in divers as potential prey, allowing us to come face-to-face with these toothy predators in shallow, crystal-clear water.

Hammerhead shark (Sphyrnidae) swimming in the Galapagos

Darwin’s Arch, The Galapagos Archipelago

Ecuador's Galapagos archipelago graces most top diving lists, be it the world's best big animal diving to best deep diving and best overall diving on the planet. When it comes to the world's best adrenaline diving, the Galapagos is no different. Located 500 miles west of mainland Ecuador in the eastern Pacific Ocean, this remote archipelago is the meeting place of several different currents. This means dives often involve being carried in strong currents alongside some of the world's most sought-after species. Darwin's Arch is the Holy Grail for those with a penchant for deep drift dives among big animals. Here, it's not uncommon to see huge fevers of hammerheads, mola mola and ginormous pregnant whale sharks - all on the same dive.

Blotcheye Solderfishes Myripristis berndti at Blue Corner, Palau

Blue Corner, Palau

Palau's Blue Corner is often touted as the world's best dive site. Located in south-east Koror, Blue Corner is an exposed reef plateau that juts out into the open ocean and is famous for its strong nutrient-rich currents that tow in the big stuff. In fact, the currents are so strong that divers hook into the plateau and hang in the blue as huge schools of barracuda, tuna, giant and bluefin trevally, king mackerel and several species of shark rip past. Yet, Palau isn't a one-trick pony. For those looking for the world's best adrenaline diving, the Rock Islands, located south of Palau, is another hotspot for blackwater diving.

Whitetip reef sharks in a deep cave in Cocos Island

Cocos Island, Costa Rica

Located 340 miles offshore from Costa Rica in the Pacific Ocean, Cocos Island is the best place in the world to dive with hundreds of scalloped hammerhead sharks. Known as the 'Little Galapagos' of Costa Rica, Cocos Island Marine Park also forms the meeting point for several nutrient-rich currents, drawing in huge bait balls, sailfish, tuna, dolphins, rays, and, of course, sharks. For those who get a kick out of deeper water, venture 100-metres deep in a deep-sea submersible in search of the elusive prickly shark.