When we departed for our 15-month trip around the world, we didn’t even pack swimsuits. But a few months in, after our first look at the coral reefs of Indonesia, we were enchanted by the underwater world. Soon, we were seeking out unique underwater adventures and planning our itinerary around them. By the end of our trip, we had chalked up over 50 dives between us, countless hours of snorkeling, and some truly weird and wonderful fish encounters. Everyone who plans a trip to Southeast Asia should have a sea life encounter, but it takes some planning and know-how to pick the best spots. Here is a list of our favorite places to see marine life in Southeast Asia.

Manta Rays: Nusa Penida, Indonesia

What: Manta rays swoop in circles around a cleaning station in a rocky bay, lining up to get nibbled by small fish. It’s a hypnotic spectacle. After a few seconds with the mantas, they became our favorite marine animal.

Where: Nusa Penida, an island off the southeast coast of Bali, Indonesia.

When: Any time of the year.

What are the chances? Excellent but not guaranteed. We were lucky and saw over 10 mantas. Our guide said that sightings of 6 to 8 mantas are more common.

Dive or snorkel? Either.

Where else? Makassar Reef in Komodo National Park is an equally reliable place to snorkel or dive with manta rays. We’re told that spring and fall are the best times for sightings.

Read more: Manta Madness at Nusa Penida
A Komodo Dive Liveaboard on a Budget

Whale Sharks: Donsol, Philippines

A whale shark in Donsol.

What: Swim with the world’s largest sharks. Whale sharks are gentle, plankton-eating giants that can grow up to 15 meters long, although 5-8 meter specimens are more common these days.

Where: Donsol, in Southeast Luzon, Philippines.

When: Plankton in the bay draws whale sharks from around January through May.

What are the chances? Excellent if you come in season. In early April 2016, it had been six weeks since the last day without shark sightings. Check beforehand, though. In 2013 and 2014, the whale sharks stayed away and a lot of tourists were disappointed. Ask around and check the blogosphere to make sure the sharks are in town before you make the long trek to Donsol.

Dive or snorkel? Snorkeling only. Diving with whale sharks is prohibited at Donsol.

Where else? Whale sharks sometimes congregate in Sogod Bay at Panaon Island near Padre Burgos on Leyte island. Check with Whaleshark Divers to find out if the sharks are in the area. Avoid Oslob in Cebu and Gorontalo in Sulawesi, where the sharks are fed to guarantee sightings. We can’t recommend these sites because feeding sharks disrupts their migration patterns.

Read more: The Whale Sharks of Donsol

Shoals of Sardines: Moalboal, Philippines

The sardine shoal off the reef at Moalboal.

What: You’re in the eye of the tornado. Millions of shimmering silver sardines swirl around you, breaking and re-forming clouds and vortices with a coordinated flick of the fin. Who would have guessed that the humble sardine, best known in a tin, puts on one of the best underwater shows we’ve seen?

Where: Moalboal on Cebu island in the Philippines. The sardines are just off the beach at Pangsama. Wade in, swim over the reef, and find the shoal over the dropoff.

When: Any time of the year. Dry season in Cebu, when travel is more pleasant, is January through May.

What are the chances? Excellent. As far as we could gather, the sardines are always there.

Dive or snorkel? Either. Both is best! Snorkeling is free and the sardines are a short swim from shore. Diving allows the best views of the formations from below. I did a shore dive with Neptune Divers for 1200 pesos.

Where else? We don’t know of anywhere quite like this! You can dive sardine shoals in South Africa, but watch out for the great white sharks.

Read more: Inside he Sardine Shoal of Moalboal

Mating Mandarin Fish: Bandaneira, Indonesia

Mandarin fish below the pier in Bandaneira.

What: This is one of the more offbeat sea life encounters of our trip. A few dozen feet from shore, in the unglamorous rock pilings in a dirty harbor, live the utterly unique mandarin fish. These diminutive swimmers are festooned with psychedelic blue, green, and orange swirls. Come dusk, the fish emerge from the crevices in the rocks and engage in a mating ritual that’s all flapping fins. It’s tricky to get close enough for a good look without scaring them back into a dark recess of the pier.

Where: In the crevices of the rocks and pilings of the public dock to the right of the Blue Motion dive shop in Bandaneira. There’s a small, littered beach that’s popular with local families. Wade carefully through the rubbish to the end of the dock on the right side facing the sea.

When: Any time of the year. The mandarin fish don’t come out of their hiding holes until sunset. Bring an underwater torch if you can.

What are the chances? Excellent, with patience and sharp eyes.

Dive or snorkel? Either. I snorkeled and was happy with what I saw. A bit of free diving was required to get a good look at the fish. Blue Motion offers shallow shore dives, where you can see other macro creatures among the rocks and pilings.

Schooling Barracuda: Sipadan, Malaysia

Barracuda vortex at Sipadan.

What: It’s a sight out of National Geographic. A school of hundreds of barracuda form a spiral pattern and swirl up to the surface, silhouetted against the sun. Then they descend and uncoil, swimming past you in a rush of silver teeth and striped backs.

Where: Barracuda Point at Sipadan, Malaysia

When: Any time of year

What are the chances? There’s a good chance of seeing a school of barracuda. It takes a bit more luck to see the vortex display. Not only does Sipadan have barracuda, you’ll see huge schools of jackfish, batfish, and sharks galore.

Dive or snorkel? Diving only.

Practicalities: Diving Sipadan requires a permit and advance planning. I dove with Sipadan Scuba and was satisfied if not thrilled with them.

Where else? Sanctum Una Una in the Togean Islands has a resident school of barracuda at the Jam dive site in front of the resort.

Read more: Diving Sipadan: Barracuda Vortex and a Fish Cave
Diving Una Una: Ending a Year of Travel in Style

Napoleon Wrasse: Banda Islands, Indonesia

A smallish Napoleon wrasse on the reef at Pulau Hatta.

What: Napoleon wrasse, with their thick lips and lumpy heads, aren’t the most beautiful fish at first glance. They’re more like the big, grumpy granddads of the reefs. At closer glance, though, you can admire the delicate gray-green patterns of their scales and appreciate their great size. There’s something oddly charismatic about these ungainly fish.

Where: The magnificent dropoff at the beach on Pulau Hatta in the Banda Islands, Indonesia. Also seen at many dive sites around the Banda Islands. Sadly, Napoleons are under threat from overfishing for the Chinese market.

When: Any time of year. The dry and calm season in the Banda Islands is October through early December.

What are the chances? Very good, unless all the Napoleons have been fished and sent to China by the time you get there.

Read more:

Coral Atolls with Deep Blue Dropoffs: The Togean Islands

Coral at Reef 5.

What: Float over offshore atolls with colorful coral formations and marine life. Small reef fish like anthias, parrotfish, Moorish idols, and triggerfish are guaranteed. Swim along the edge of the reef and watch the rays of sun pierce the crystal-clear blue abyss.

Where: The Togean Islands in Sulawesi, Indonesia. The best snorkel spots are Bomba Atoll, Reef 1 (aka Hotel California), and Reef 5.

When: The dry season in the Togeans, when seas are calm and visibility is the best, is from around March through October. The reefs are best seen under sparkling sunlight.

What are the chances? Great views of coral and deep blue sea are guaranteed. Big fish sightings are less common, although you will see hundreds of species of smaller fish.

Dive or snorkel? Both. There’s nothing like snorkeling the top of a coral atoll with lots of light giving color and life to the surroundings. All the resorts run half-day or full-day snorkel trips to the offshore reefs.
Sanctum Una Una is the best dive shop in the Togeans, although most resorts have dive operations.
Where else? Pulau Hatta in the Banda Islands has a dramatic dropoff only meters from the shore. It’s probably the best snorkel spot in the world that’s accessible from the beach.

Read more: Poya Lisa: Cats, Coral, and Birdwatching in the Togean Islands
The Last Stop: Malenge and Bolilanga

Underwater Psychedelia: Batu Bolong, Komodo, Indonesia

What: This pinnacle in the north of Komodo National Park is home to more fish than any other dive site we’ve seen. Deep down, trevallies hunt schools of fish while Napoleon wrasse, sharks, and groupers lurk around the coral. Closer to the surface, sunlight illuminates healthy coral and millions of red anthias. It’s a psychedelic underwater spectacle.

Where: Komodo National Park, Indonesia

When: Komodo can be dived year round, but the best conditions in the north, where Batu Bolong is located, are from April through October. We visited in May when the conditions were great but the sites weren’t crowded.

What are the chances? It’s hard to imagine not having a fantastic dive here, although the amount and types of fish will be different every time.

Dive or snorkel? Either, although diving is better. Snorkeling is possible with a guide who is familiar with the area’s strong currents. Batu Bolong can be visited on a liveaboard or dive day trip from Labuanbajo. Batu Bolong is subject to strong currents, so choose a reputable operator who can time your visit to coincide with favorable tides.

Where else? Pinnacle 1 at Una Una Island in the Togeans, has almost as many fish. Highlights from my two dives here were the clouds of purple anthias and school of Napoleon wrasse.

Read more: Island Hopping in Komodo (Flores XP)
A Komodo Dive Liveaboard on a Budget

Save our Seas

Unless you’ve been living under a rock for the last few years, you should know that our oceans are under threat. Overfishing, coral bleaching, and plastic garbage threaten the survival of all the wonderful species I’ve described. If you visit any of the places mentioned in this blog, think about what you can do to help preserve them. Environmentally sustainable tourism may be the best hope for preserving these underwater wonders.

At home, you can help preserve marine life by choosing to eat sustainable seafood. Seeing the underwater world made me reconsider my food choices. Before our trip, I was a pescatarian: vegetarian except for fish. Learning about the ocean’s wonders made me re-assess some of my food choices. Now, I don’t eat much seafood except for wild Alaskan fish, which is sustainably managed. I’ve started to think that an occasional serving of locally raised, organic chicken or turkey is more sustainable than industrially harvested fish. I also recommend the Monterey Bay Aquarium Seafood Watch to help you choose sustainable seafood.

To learn more about how humankind is harming marine ecosystems, visit the Pristine Seas project at National Geographic. It explores the least-touched marine landscapes on earth, documenting what truly pristine ocean habitats should look like. Get the gorgeous Pristine Seas book by Enric Sala and drool over photos of magnificent, untouched reefs.