Dive with hammerhead sharks at Cocos Island

Cocos Island, in the deep Pacific, some 550km off the Costa Rican coast, is one of the top dive destinations in the Americas and together with the Galapagos one of the best destinations for marine wildlife in the Eastern Pacific.

It’s also the site of one of the great underwater spectacles – the mass schooling of hundreds of hammerhead sharks.

Each year, from June through October, they gather in uncountable numbers, attracted by high concentrations of prey. Cocos Island sits at a convergence of swirling, nutrient-rich currents, attracting vast schools of fish on which the hammerheads feed.

Whale sharks are also regular visitors to the waters around Cocos, making it a popular location for wildlife filmmakers.

Are hammerhead sharks dangerous?

Although officially tagged as a ‘man-eater’, hammerheads are shy of humans and attacks are extremely rare. They hunt on the ocean floor at night, feeding on stingrays (their favourite food), squid, mackerel, sardines and octopus.

Why do they have a strange-shaped head?

Their strange hammer-shaped head contains hundreds of small electrical sensors that they use to detect the faint electromagnetic fields generated by their prey hiding beneath the sand.