Coiba

Inscribed by UNESCO in 2005 and centred on the largest island in Central America, Coiba National Park protects roughly 2,700 km² of islands and tropical eastern-Pacific sea in Panama's Gulf of Chiriquí. Because Coiba served as a feared penal colony for most of the 20th century, its forests and reefs were left largely undisturbed, and the park now shelters close to 760 fish species, about 33 shark species, and around 20 species of whales and dolphins. Diving is reached by day-boat or liveaboard out of the fishing village of Santa Catalina, a 60–90 minute crossing. The signature draw is sheer abundance: dense resident schools of white-tip reef sharks stacked on the sand, walls of bigeye jacks, snapper, and barracuda, plus bull sharks at exposed pinnacles and seasonal whale sharks and mantas in plankton-rich water. Conditions are genuinely variable—Pacific upwelling drives thermoclines that can drop water from a balmy 28–30°C surface to a green, 18–24°C chill below, and currents range from gentle to strong at offshore sites such as Montaña Rusa. Visibility is best in the December–April dry season (often 20–30 m) and drops when plankton blooms feed the big animals.

• Coiba is the largest protected marine ecosystem in the tropical eastern Pacific and a UNESCO World Heritage Site (inscribed 2005), spanning roughly 2,700 km² of islands and sea. Its waters host close to 760 fish species, about 33 species of sharks, and around 20 species of whales and dolphins—biodiversity preserved in part because the island spent most of the 20th century as an isolated penal colony.
• Resident white-tip reef sharks are the signature sight, often seen stacked motionless on the sand or stacked in caves in large groups; sites also deliver schooling bigeye jacks, snapper, and barracuda, with bull sharks at exposed pinnacles such as Punta Peligro and occasional hammerheads at offshore Montaña Rusa.
• Pacific upwelling drives strong thermoclines: surface water is typically 26–30°C, but from roughly mid-March to June cooler, nutrient-rich water of 18–24°C can rise on the dives, often arriving green and reducing visibility—the same nutrient surge that draws plankton-feeding whale sharks and mantas.