This article was originally published on the flight comparison site Skyscanner.
Some of the best snorkeling and diving spots in the world can be found in Malaysia, Thailand, Indonesia and the Philippines, where warm tropical waters and strong currents provide ideal conditions for beautiful coral reefs and abundant marine life.
And even better, these dazzling dive destinations are nearby and relatively inexpensive.
The only volcanic island in Malaysia, Sipadan has one of the richest marine habitats in the world. Strong currents and steep walls provide a conducive gathering point for thousands of fish species and hundreds of coral types.
On a dive, it's common to see sea turtles, bumphead parrotfish, eagle rays and a variety of sharks including white-tipped reef sharks, hammerheads and whale sharks. For most divers, the highlight is the unmissable Barracuda Point, where shoals of barracuda and trevally fish swarm around in spectacular formations.
Do book your dives early though, as conservation rules only allow 120 diving permits every day.
An incredible diversity of dive sites await in beautiful Bali.
The pristine coral reefs of Nusa Penida and Nusa Lembongan provide a picture-perfect backdrop for the fascinating and huge Mola-mola fish, which grow up to 4m in length and are the largest bony fish in the world.
Check out some spectacular wall diving at the Drop Off, hunt for pigmy seahorses in the northern waters, spot peacock mantis shrimp in the the Coral Garden, and explore the ever-popular "Liberty" shipwreck in Tulamben.
Moalboal, Cebu, Philippines
With an unusual fringe reef that extends outward from the shore with gently increasing depth, Moalboal is perfect for beginner divers and snorkellers.
For more advanced divers, there is Pescador Island with the exciting vertical tunnel of the Cathedral, the strong currents and gorgeous fish swarms at Sunken Island, and steep drop-offs at Sampaguita and Tongo Point, where it's common to see turtles, coral gardens, and sometimes even whale sharks.
Other attractions include the charming village-like atmosphere of Panagsama Beach, and adventure activities like canyoning, trekking and mountain biking in the nearby jungle-covered mountain valleys.
Northwest of Phuket lies the clear blue waters, huge boulders and coral sand beaches of Similan, home to some nine islands with awesome snorkeling and diving spots.
An astounding diversity of diving experiences awaits, from coral walls and caves to sea fans and swim-throughs.
Top dive sites include Christmas Point, with its dramatic archways teeming with trevallies and tuna, the oddly-shaped rocks of Elephant Head, the beautiful reef fish at East of Eden, and a sunken Chinese wreck.
Tenggol, Trengannu, Malaysia
Off Malaysia's east coast is the tiny island of Tenggol.
A well-kept secret in the diving community, it has spectacularly steep rocky cliffs that descend 48m in depth, making for some fantastic wall diving.
More than 20 different pristine dive sites offer colourful carpets of hard and soft coral, shoals of bumphead parrotfish, lizardfish, and barracudas.
Divers have even also sighted many eagle rays, black-tipped reef sharks, and whale sharks among the diving spots!
Bonus: there are two wrecks - an oil tanker only 14m deep, and a wartime Japanese landing craft.