Visibility is a big factor when divers decide where to drop into the water because the clearer the water, the more a diver will see. Even the biggest whale is invisible in water that is too murky. The heavy rains that have fallen country-wide have clouded many of Costa Rica’s dive sites with brown river runoff.
Luckily, Cocos Island, 365 miles west of Puntarenas on the Pacific coast, and Caño Island, in the Osa Peninsula in southern Costa Rica, are far enough offshore to escape the vast area of dirty water off the continent. The rain actually contributed to great diving there. The islands were not completely spared—the downpours rendered the island’s dive sites murky for a few hours, but since ocean currents are far stronger than any paltry island river, the tides washed away all the rainwater.
The mixing of nutrients from the rivers into the ocean never fails to bring massive quantities of marine life. The food chain starts small and gets big, from anchovies to whales. But divers don’t just want to know it’s there, they want to see it.
The blue water throughout Cocos Island has dominated any rain, even though the cold, green water below has been holding to below 100 feet. Ironically, the super clear water makes it slightly more difficult to see the big groups of hammerhead sharks that divers come to Cocos to see. But the sharks are still there, along with every famous beast of the eastern tropical Pacific.
Blue water mixing with cooler thermoclines at Caño Island has created advanced diving conditions on many days with heavy current and surge. Fish thrive in currents and can be found where the current is strong. The trick for divers is to not lose their buddies while being blown about by currents in thick dark clouds of fish. A whitish layer of rainwater on the surface created some strange and beautiful lighting on the bottom of the sea.
The Pacific’s offshore blue water has been transparent as usual because the water is defined by its lack of land sediments. The blue water has hovered only a few miles beyond Caño Island, but it is accessible from the entire Pacific coast. Off Caño Island and the Osa Peninsula, multiple species of thousands of dolphins, together with tens of thousands of tuna, some sailfish and marlin, and a few sharks and assorted other creatures, have been feasting on bait balls of little fish and crustaceans that may cover hectares.
Hundreds of olive ridley turtles, often mating, have been dotting the surface of this deep water. The clearest water in Costa Rica remains unaffected by rain. The question is, how far out is it today?
The Caribbean and Guanacaste, with dive sites close to rivers, have had some rather dirty days, but both are showing signs that this spell of heavy rain has passed. One thing is for sure, all conditions will have changed by the time you read this, but rest assured, somewhere in Costa Rica, there is always excellent diving to be found.