The best diving spots in southeast Asia

This stunning group of islands at the eastern-most point of Indonesia is often featured in ads by the Indonesian Tourism Board. The best way to marvel at this exceptional underwater landscape of never-ending colourful reef walls where hard and soft corals compete for space is to do a liveaboard and hop around the various dive sites. Famed for its biodiversity, spottings of wobbegong sharks, whitetip reef sharks, manta rays, batfish and large schools of tuna and mackerels are common.

Dive season: All year around.

Difficulty level: All levels, although some dive sites are not recommended for beginners or those not comfortable in currents.

These nine granite islands lie about 100km northwest of Phuket and are part of Mu Koh Similan National Park. The park is only open during dive season, which provides the best chance of spotting manta rays and whale sharks. The sites on the east coast are generally easier with gentle sloping coral reefs while the west is slightly more challenging due to its giant granite boulders, fan corals and incredible submarine rock formations. There are also some dive sites for muck diving – so watch out for critters like ghost pipefish and sea moths.

Dive season: Late October to early May.

Difficulty level: Beginners to mid, plenty of easy dive sites with weak to moderate currents. 

Sipadan Island is often hailed as one of the world's best dive sites – and for good reason, too. Where else in the world can you witness a hypnotic barracuda vortex and swim inside a huge school of whirling jackfish? Sipadan is an oceanic island off the coast of Sabah, Malaysia, sitting atop an extinct undersea volcano and surrounded by almost 1,900ft deep canyons – all of which combined makes this spot a rich marine habitat.

Dive season: All year round, best months from April to December.

Difficulty level: Mid to advanced, expect some strong currents and drifts dives.

Somewhat less well-known, Layang Layang in Malaysia is famous for its scalloped hammerhead sharks. If you're lucky, you might catch a glimpse of a school of them gliding by, making the trek out to this island entirely worthwhile. Manta rays often frequent this deep water area. Shore dives are possible although visibility is only around two to four metres near the pier.

Dive season: All year round, but higher chances of shark spotting during mating season in April to May.

Difficulty level: All levels, about 12 dive sites in total.

Declared a world heritage site by Unesco in 1993, the Philippines' Tubbataha Reef National Marine Park is teeming with marine life – but to get there, you'll need to do a liveaboard, making it one of the least crowded dive spots in the Philippines. Located in the middle of the Sulu Sea and in the middle of the ‘Coral Triangle’, you can find sharks, hawksbill and green turtles and small reef fish congregating. 

Dive season: March to early June.

Difficulty level: All levels.

Divers come to Malapascua near Cebu for one reason and one reason only – to observe thresher sharks in their natural habitat. This area is reputedly the of one of the only places in the world where the thresher shark can be seen within the limits of a recreational diver, although there's plenty of other fish in the sea as well. Macro diving is pretty popular too – seahorses, cuttlefish, pipefish are among those found on the seabed.

Dive season: All year round.

Difficult level: Mid to advanced.

Getting to the Banda Islands in the Molucca region of eastern Indonesia is a pain. But once you arrive, you'll find its inaccessibility is a blessing because its reefs and marine life are as healthy and untouched as they come. Do a liveaboard to truly experience the diversity of the archipelago's 11 islands, of which seven is inhabited.

Dive season: All year round, each season offers a different experience.

Difficulty level: All levels.