There are many great reasons to scuba dive, but the one that most captures people’s imagination is marine wildlife. 
From schools of tropical fish to sharks, tropical seas house an impressive chunk of Earth’s life that most people only ever see on the Discovery channel. Still, as a diver, I firmly believe that swimming with a school of fish or sharing a manta ray’s habitat for a few minutes is about more than recreation.
Seeing the ocean animals in their natural habitat makes them seem more real and worth protecting than any TV program could. At each of these five incredible destinations, divers can get up close and interact with some of the planet’s most powerful and beautiful animals. The action is just below the surface at many of these sites, so even novice divers can participate.
1. Palau – There are a whole host of good reasons to dive in Palau, a tiny island nation in the south Pacific. The islands have been famous as a wreck diving site since 1969, when Jacques Cousteau came to Palau’s Chuuk Lagoon in 1969 to film the wreckage of Japan’s Pacific fleet, most of which sunk there during World War II. The wrecks have since been colonized by a variety of marine life that includes corals, rays, turtles, and over 200 species of fish.
Above all, Palau is known for it’s sharks, with some 130 threatened species inhabiting the islands. To protect the islands’ ecosystem, Palau’s government in 2009 named the country’s waters a ‘shark sanctuary’, banning all commercial shark harvesting. Divers are likely to run into grey reef sharks, whitetips, and other species patrolling both wrecks and wall sites like Blue Corner.
2. The Great Barrier Reef – While most Americans would be hard-pressed to find Palau on a map, even non-divers know the Great Barrier Reef. Running nearly 1,500 miles down the eastern coast of Australia, the Great Barrier Reef is the largest reef in the world and is said to be visible from space. To go with its size, the Great Barrier Reef has an almost unfathomably large collection of sea life. Besides moray eels, wrasse, and other common coral-dwellers, rarer creatures like giant clams and sea snakes abound.
Visiting the Great Barrier Reef by car is a good alternative for those who aren’t willing to commit to a liveaboard: the GBR is probably the world’s most road trip-friendly reef, and many people choose to town-hop down the coast, doing their diving by day boat. From Cairns on the reef’s northern end, divers can catch a boat out to Hamilton Reef, a favorite spot for marine mammals like dolphins and Minke whales. Moving south, Townsville is the base for trips to the SS Yongala, a 1911 wreck-turned-reef that now sports turtles, large sea snakes, and other super-sized animals. Gladstone, located further south, is the connection point for boats to Heron Island, said to have some of the best diving on the GBR.
3. Galapagos Islands – Known for inspiring Darwin’s theory of evolution, Ecuador’s Galapagos Islands are now a UNESCO World Heritage Site and a reserve for one of the world’s largest populations of endemic wildlife. With the waters around the islands protected, the local fish have very little fear of humans, and many will even approach divers. Sea lions, turtles, and manta rays are everywhere, and starfish, sea cucumbers, and Galapagos crabs seem to cover the sand in some spots. Sharks, including hammerheads, are common but not dangerous. Diving in Galapagos is tricky, and really only for experienced divers.
The islands are unusual for the tropics in that most of the diving is on volcanic drop-offs instead of coral reefs, so dive sites are deep and very exposed to ocean currents. Thanks to the Antarctic Humboldt current, which passes by the islands, the water is unusually cold for the equator; a 7mm wetsuit is standard gear. If you’re planning on going to Galapagos, keep in mind that all visitors, whether Ecuadorian or foreign, need an INGALA transit card to visit the islands; the card costs $10 for foreigners and must be purchased before going to Galapagos. Visitors also have to pay a park fee ($100 for foreigners) upon arrival in the islands.
See more articles about Ecuador and the Galapagos Islands and photos of Ecuador
4. Cocos Island, Costa Rica – Costa Rica is famous as an eco-tourism destination, and few places in the country are better for it than Cocos Island, a rainforest-covered spot of land 340 miles off Costa Rica’s Pacific shore. Accessible only by liveaboard, Cocos is one of the largest uninhabited islands outside of the Arctic: the only residents are a group of about 30 park rangers. While visitors can land for day hikes and other activities, they have to be off the island by nightfall.
Cocos is an oceanic island, so visitors can expect to see an eclectic mix of animals, including octopuses, 
hawksbill turtles, tuna, and hammerhead and whitetip sharks. The island is especially famous for whale sharks, most often sighted in deep, off-shore sites like Dirty Rock, a 100-yard-wide underwater channel northwest of the island. As in Galapagos, the diving in Cocos is generally on the deep side and in strong current, so it’s not for beginners. With sea kayaking and whale-watching nearby, divers shouldn’t have a hard time keeping themselves occupied during surface intervals.
5. The Red Sea – Europeans have been diving the Red Sea for decades, but it’s only been in the past few years that American divers have begun to join them. The 1,200-mile-long sliver of water has an impressive variety of habitats available for divers to visit, from coral reefs in the south to deep walls and wrecks in the north. The Egyptian city of Sharm El-Sheik has become the base for Red Sea diving; from there, visitors can board a liveaboard or take day trips to coastal sites.
The extra-saline Red Sea’s marine life is much like that found in the Indian Ocean, with a few endemic species like the blue-cheek butterflyfish thrown in for good measure. There are loads of sponge and coral species, dolphins, sharks, and tropical fish like anthias and clownfish. At 1,200 miles long, there’s plenty of Red Sea to explore, and divers may even need multiple days to exhaust the possibilities at enormous offshore sites like Daedalus Reef.
rock froze in place and trained their eyestalks on us, skittering away when we drifted too close. From a grotto in the lava cliff high above our heads, a pair of Blue-Footed Boobies peered down at the Queen Mary as divers moved about the deck, donning scuba equipment and checking computers. Clearly, we were causing a bit of a stir.
the waters of the archipelago support a wide variety of sea life, including marine iguanas, dolphins and several species of shark. It’s a kind of aquatic Wonderland, where cold-water species like the Galapagos penguin swim among schools of gaudy tropical fish.
need for sustainability,” Watkins wrote on the group’s website. ” It is our fervent hope that we can create a truly sustainable society that cares for these islands .”