Many islands, reefs, caves, and rocks lie off the coast of Costa Rica, providing excellent spots for underwater exploration. Visibility varies with season and location. Generally, heavy rainfall tends to swell the rivers and muddy the waters, even well offshore.
Banana plantations and their runoff have destroyed most of the Caribbean reefs, although there's still good diving at Isla Uvita, just off the coast of Limón and in Manzanillo, down near the Panamanian border.
Most divers choose Pacific dive spots like Caño Island, Bat Island, and the Catalina Islands, where you're likely to spot manta rays, moray eels, white-tipped sharks, and plenty of smaller fish and coral species. But the ultimate in Costa Rican dive experiences is a week to 10 days spent on a chartered boat, diving off the coast of Cocos Island.
Diving off the Shores of Isla del Coco (off the Pacific coast): Legendary among treasure seekers, pirate buffs, and scuba divers, this small island is consistently rated one of the 10 best dive sites in the world. A protected national park, Isla del Coco is surrounded by clear Pacific waters, and its reefs are teeming with life (divers regularly encounter large schools of hammerhead sharks, curious manta rays, and docile whale sharks). Because the island is so remote and has no overnight facilities for visitors, the most popular way to visit is on 10-day excursions on a live-aboard boat, where guests live, eat, and sleep onboard -- with nights spent anchored in the harbor.
|Costa Rica does not only offer virgin rainforest, fascinating volcanoes and pristine beaches but also an overwhelming world of undersea wildlife. A a distance of 2 to 15 miles offshore in the northwest of the country from Nicoya peninsula the archipelago of the Catalina Islands is to be found that consists of about 20 rocks of different sizes. A little bit further north, Bat Island / Isla Murciélagos is located.|
|The exposed location of these islands guarantees an abundant variety of sea wildlife which is hardly to be found somewhere else. For some reason - unexplored up to now - the Catalina and Bat Islands are a melting pot of very different undersea wildlife and fish that usually do not occur together. With good luck, even whale sharks are to be seen at Bat Island.|
|Visibility||Is about 18 to 75 ft., and strong currents have to be expected once in a while. But you will be highly recompensed by a spectacle that does not allow even one minute of boredom: huge schools of snappers, sharks, eagle mantas, turtles and barracudas are awaiting the diver as well as an immense variety of other tropical fish and reef wildlife. The huge mantas rays are to be seen between November and May; and one of the giant turtle species can be met all year round.|
|Water temperature||Is between 75 and 85° F; diving season is all year round since there are no bigger rivers here that could transport stones and mud during the rainy season and would thus affect the good view. Between the end of November and end of February, the diving trip to Bat Island may not always take place since at this time of the year, a strong coastal wind from the north (Papagayo) may hinder the boat to leave the harbor. Short term, bookings are then switched to the Catalina Islands.|
|Marine Life Around Catalina Islands||The best months for diving the Catalina Islands are December through May, where we have seen up to 50 Manta Rays with wingspans of 14 to 20 ft on a single dive.|
|Marine Life Around Bat Islands||The optimum months for the long range trip to the Bat Islands are March through November. Here we see the impressive 8 to 15 ft bull sharks, schools of cow-nosed rays, eagle rays and horse-eye jacks, spade fish, pompano, snapper and Wahoo.|
|Marine Life on Local Dive sites||The local dives offer many white tip reef sharks, giant schools of grunts and yellowtails, spotted eagle rays, turtles, gigantic stingrays, angel fish, octopus, sea horses, starfish, frog fish and many species of eels. With some luck, you will be able to see also whale sharks up to 35’ long as well as spinner dolphins, humpback whales, pilot whales, Orcas and false killer whales.|
Isla del Caño and the Osa Peninsula coast are part of mammoth (Rio Sierpe, Rio Terraba, Caño Island) marine ecosystem.
Isla del Caño is located on the South Pacific coast of Costa Rica, in front of Drake Bay. It is a Biological Reserve, protected under the our National Park System. It has 320 Has. (800 acres) of land and 2700 Has. (6672 acres) of marine habitat. The abundant marine life and coral are almost unique for Pacific waters in Costa Rica.
The Osa Peninsula reaches out into the Pacific ocean from southwestern Costa Rica and is described by National Geographic as "the most biologically intense place on earth" More than 1,000 acres of mangroves wetlands and 1,000 miles of fresh and salt water rivers, estuaries an tributaries interact with the Pacific ocean through tides, which provides for an incredible abundance of marine life.
|Marine life||Around Caño Island you may encounter Humpback whales, Dolphins, Reef Sharks, Giant Manta Rays, Mobula Rays, Sea Turtles, Groupers, Snappers, Angels, Moorish Idols, Trumpet fish, various types of Eels, Crustaceans, Huge schools of Barracudas, Jacks, Grunts and much more.|
|Coral Formations||The soft and hard Coral formations are common, but not as colorful and abundant as in the Caribbean. There are 15 or more types of stony coral species as well as the attendant coral eaters (star fish, mollusks and hermit crabs) The terrain varies widely and includes 20' reefs, 50' underwater pinnacles, canyons, walls and caves.|
|Dive site||The dive trips are usually a full day adventure, leaving in the morning and returning in the late afternoon.|
|Visibility||The visibility varies from site to site, but is usually no lower than 40' and up to 100' plus making it the best in mainland Costa Rica.|
|Temperature Range||High 70's to Low 80's with thermo clines at varying depths.|