This Costa Rican Island Is Known For Having One Of The Best Shark Dives In The World

As one of the most biodiverse regions on Earth, Costa Rica is a natural bucket list destination for wildlife spotters and adrenaline junkies alike. While many travelers focus their efforts on the rainforests, waterfalls, and sun-kissed beaches, the spectacle continues just beneath the surface. With its nutrient-filled waters, the Pacific side of this earthly paradise attracts an abundance of wildlife, including huge schools of hammerhead sharks.


If you think seeing one of these uniquely-shaped predators is exciting enough, imagine seeing them arrive by the hundreds, elegantly cruising the currents in search of food. That's the beauty of Bajo Alcyone, a busy dive site near Cocos Island National Park. This remote gem sits 342 miles from the mainland of Costa Rica, serving as the inspiration for Isla Nublar in the 1990 book "Jurassic Park" by Michael Chrichton. In the 1993 movie adaptation, you may remember this scene when the helicopter revealed the gorgeous island and the crew landed in front of a towering waterfall.

That's Cocos Island in real life. This important terrestrial and marine habitat is one corner of the "Hammerhead Triangle," a migration route between the Galapagos Island and Malpelo that draws in tiger sharks, silky sharks, Galapagos sharks, green turtles, and hammerheads, making it one of the best dive sites to view large species on the globe. In these waters, it's not a matter of if you see a shark while diving, but a matter of when.


What to expect at Bajo Alcyone near Cocos Island

There are 20 dive sites around Cocos Island, including Bajo Alcyone. It's notoriously choppy, so you'll follow a mooring line — hand over hand — down about 80 feet, positioning yourself inside a crevice in the rocks to look up. Within minutes, the sharks will make an appearance in staggering numbers above you. This species, in particular, is the scalloped hammerhead, and scientists are still perplexed about why they form such large groups, as sharks are typically solitary creatures. At 20 feet long and more than 1,200 pounds each, let's just say this is not your typical school of fish. In fact, you'll be looking at one of the rarest sights in the world.


While best known for hammerheads, there's plenty of majestic animals that grace the waters around Cocos Island, including 11 other species of shark, giant mantas, whale sharks, dolphins, orcas, green sea turtles, and hawksbill sea turtles. Most excursions range between 8 to 10 days long, giving you ample viewing opportunities. Only one tour group is allowed at each diving site at a time, so the only crowds will be the animals. You truly are in the middle of nowhere and, in this case, it's well worth it.

What to know before you go

Diving around Cocos Island is easily one of the most amazing things to do in Costa Rica, so long as you have your advanced diving certificate. Due to its remote location, the only way to view the hammerheads is by taking a tour on a liveaboard ship for a week-long excursion. The tours are so popular that they often book out 12 months in advance, so be sure to reserve your spot as soon as possible. The tours range from $4,724 to $5,960 per trip.


Your journey will start at San Jose International Airport (SJO), where your host will pick you up and drive you two hours to the coastal town of Puntarenas. From there, you'll board a ship and sail 36 hours toward Cocos Island National Park. Beyond the park rangers, no one is allowed to live on the island, so your home will be the boat and the open sea. The good news is, you'll be surrounded by divers who love swimming with sharks just as much as you do, so there will be plenty to talk about.

For the best chance at viewing the hammerheads, book a tour from June through December, when the plankton blooms entice the sharks and mantas alike. If you have fewer dives under your belt, opt for the dry season from December to May, when the currents will be less intense. No matter when you decide to book, this is one trip you'll remember for a lifetime.