IN THE AQUAMARINE seas some 330 miles off Costa Rica’s Pacific coast lies one of the most pristine islands on Earth. Spanning nine square miles, the rectangular landmass is called Isla del Coco, or Cocos Island. A cloud forest breathes there. Waterfalls pour from jagged cliffs into rushing rivers, and rain-soaked jungles shelter some 400 insect species and 156 species of birds, including the endemic Cocos finch. In 1978, Costa Rica declared Cocos Island and its surrounding waters a national park. Today, it is uninhabited except for the park rangers, paramedics, and volunteers who live there. It is so remote that, aside from the pigs, deer, cats, and rats that humans brought to the island starting in the 16th century, it has no native mammals.
Cocos is even more revered for its spectacular marine life. Within its cold, nutrient-rich under-water corridors, where two currents collide, hundreds of species such as manta rays and sea turtles float and flit. The biggest stars of Cocos Island, however, are its sharks. Sometimes called “Shark Island,” it sits amid seas containing some of the largest schooling populations of critically endangered scalloped hammerhead sharks; its waters also support the gigantic whale shark, and tiger, thresher, and silky sharks. The legendary French ocean explorer Jacques Cousteau, who made countless dives into the turbulent currents surrounding Cocos starting in 1976, reportedly called it
