The world’s best dive sites offer everything from challenging to gentle dives and relaxing snorkeling to wreck diving. The best-known dive site on the globe is the Great Barrier Reef, where an enormous coral reef system is home to thousands of marine species, many of which boast vibrant colors. The reef can be explored by all levels of divers on daytrips from Cairns.

For more challenging diving, head for South Africa’s Outer Anchorage, where sharks and boulders await. Meanwhile, an eerie, yet fascinating diving experience can be had in the cool waters of the English Channel, where over 100 submarines lie at the bottom. For even more wrecks, Bermuda’s 400-plus wrecks offer unlimited wreck diving in shallow, easily accessible waters.

Great Barrier Reef, Australia The largest coral reef system in the world is a UNESCO-protected World Heritage site offering amazing marine life and abundant dive sites. Organized trips to the reef are plentiful and cater for all levels of divers, from beginners to qualified dive masters. Those who aren’t PADI certified can enjoy snorkeling among friendly, colorful fish.

Poor Knights islands, New Zealand New Zealand’s most popular dive site ranks as one of the world’s best, with its great visibility, abundant marine life and interesting deep-water caves. Protected as a marine reserve, the islands sit off the North Island and are the remnants of an ancient volcano.

Bermuda As home to more than 400 shipwrecks, many of which sit in shallow waters, Bermuda is a diving haven. In addition to easily accessible wrecks, the island boasts unbeatable visibility, warm waters and the northernmost coral reef in the Atlantic.

Cozumel, Mexico Cozumel on the Mayan Riviera is not only a top holiday resort, but it also offers world-class diving and snorkeling. The Palancar and Columbia coral reefs here draw qualified divers with the rare whiskered toadfish. Dive shops are ubiquitous in Cozumel, meaning you can shop around.

Koh Tao, Thailand Thailand’s unspoiled Koh Tao in the Gulf of Thailand boasts cheap dives, affordable accommodation and some of the best dive sites in the region. With dive sites situated just 10 minutes offshore, frequent sightings of whale sharks and the Chumphon Pinnacle dive site, the perks of diving here are many.

Florida Keys, US The only living coral barrier reef in continental US can be found in the Florida Keys, with the region’s protected waters home to shipwrecks and colorful marine life. Diving and snorkeling trips can easily be organized here, as well as glass-bottomed boat trips for those who like to stay dry.

Raja Ampat islands, Indonesia Offering perhaps the best diving in Asia, Indonesia’s Raja Ampat Islands are a diving haven with their incredible and diverse fish species and 1,500-plus islands. Top dive sites here are Bird’s Head peninsula and Fak Fak, Kri, Triton and Misool islands, the latter which sit in what is known as the Coral Triangle.

Outer Anchorage, South Africa Providing some of Africa’s most challenging and adventurous diving, the Outer Anchorage is not a suitable dive site for the faint hearted. Featuring craggy reef, rocky summits and unpredictable boulders, the reef is also a feeding site for sharks. Visibility here varies, making it important to plan your trip during optimal weather conditions.

Anzio, Italy To the south of Rome sits this popular Italian dive site, where WWII wrecks await divers. Discover the eerie wreck of the HMS Janus on a historical dive or check out the final resting place of a number of other ships lost in battle. If you are into wreck diving, Anzio is a great choice.

English Channel, England The English Channel doesn’t offer the warm waters or glamour of other dive sites, but it does have some fascinating wrecks that make for superb wreck diving. Of particular interest are the 100-plus submarine wrecks that lie at the bottom of the Channel, among which are a number of German U-boats.