Still relatively new as a diving destination, most of the diving in Costa Rica is concentrated in two areas: Flamingo-Coco (in the Gulf of Papagayo) and around the Osa Peninsula in the south west.  

Scuba diving around the Osa Peninsula is done at Caño Island, a small island about 20km from Drake Bay (a small bay on the north side of the Osa Peninsula).  Protected as a biological reserve by the Costa Rican Government, the water surrounding the island is pristine and teeming with life. 

The Gulf of Papagayo has volcanic rock formations and soft corals. However, the abundance of plankton in the water means the visibility is frequently low.  From here, you can go further afield to the Catalina and Bat islands. 

Corcovado National Park (near Drake Bay) has Costa Rica's last primary rainforest.  National Geographic has called it "the most biologically intense place on Earth".  You can't, in all honesty, be in Costa Rica without visiting it.  Fabulous tropical birds (scarlet macaws, tiny hummingbirds, toucans); wonderful mammals (howler, spider and white-faced monkeys) and the coati, a racoon-like creature.   Illegal logging, goldmining, hunting, and pollution all continue to threaten the region, even around protected areas - go while you still can . . . .

Catalina and Bat Islands - home to some of the best of Costa Rica's diving, the diving here is quite advanced due to strong currents. These islands attract rays, sharks, angelfish, grunts, snapper, octopus as well as many species of eel. Manta rays are most commonly seen at the Catalina Islands between December and April. If luck is on you side, may even see whale sharks, spinner dolphins, humpback whales, pilot whales, orcas, false killer whales and schools containing hundreds of Mobulas and thousands of cow-nosed rays.  These are longer distance dive sites (1 to 2 hours' boat ride from Ocotal on the Gulf of Papagayo).

Caño Island (just off the Osa Peninsula) offers a wide variety of marine life but the pelagics are the reason for coming. Schools of mobula rays (devil rays), turtles, and white tip reef sharks can regularly be seen. On almost every dive, the large schools of fish swimming around and overhead can be breathtaking. Sometimes the numbers are so great that sunlight can actually be blocked by these large schools of fish, creating an underwater eclipse. Although not as common, the elusive whale shark and the giant bull shark are often spotted in the area. Water visibility is good and can range from 45-90 feet.

• Some of the best diving is to be had during the rainy season (May to November).  The rain brings more nutrients content to the water and this, along with the warm water temperature, allows plankton to thrive forming the basis of an extensive food chain that encourages a whole range of creatures to visit the area.
• Moderate to low risk of malaria. Check for up-to-date information before travelling.