Cocos Island is a relatively young, large volcanic pinnacle which rises from the depths of the Pacific Ocean off the coast of Costa Rica. Here the island encounters the northern equatorial counter-current which brings warmer waters from the West Pacific and causes nutrient rich cold water up-wellings from the depths, which help to feed and support a staggering amount of marine animals. Cocos Island is known as the best place in the world to dive with large schools of hammerhead sharks and other large pelagic fish species including manta rays. There are also regular encounters with pods of dolphins and other cetaceans.
The island was formed around 2 million years ago, and is a rugged landscape covered in tropical moist forest ecology. As it is bathed in relatively warmer waters year round the climate is wet and humid, a perfect combination for healthy plant growth. It is the only oceanic island in the eastern Pacific region with such climate and ecology. Cocos has nearly 250 flowering plant species, of which 70 are endemic to the island itself, and also supports more than 30 species of coral, 60 species of crustaceans, and over 300 species of fish. This is why Cocos Island National Park is considered the jewel in Costa Rica's extensive National Parks and protected areas system, and is listed as a UNESCO World Heritage site.
Weather around the island is generally mild and wet all year round. The rainy cooler season tends to run from July to October, with visibility slightly more reduced during these months. And the drier, sunnier season starts from November through May, with increased visibility underwater. As the island receives over 750 cm (25 feet) of rain annually, there is always a slight chance of precipitation during any trip there.
As Cocos is located approximately 525 km (330 miles) from the Pacific shore of Costa Rica, and there is absolutely no overnight stays allowed on the island, the only way to dive there is by liveaboard. There are only five boats which have permits to operate diving trips to the National Park, and all of these vessels depart for minimum 10-day long trips from Puntarenas on mainland Costa Rica. Guests should stay one night in San Jose before the trip departure date to ensure they do not miss departure. Cocos is a one and a half day sail from port, so guests should be prepared for lengthy open sea crossings.