Costa Rica
Five hundred kilometres off the Pacific coast of Costa Rica, rising from the deep ocean like a emerald fortress, Cocos Island has earned its reputation as one of the planet's supreme diving destinations and one of the most biologically significant islands in the Eastern Pacific. Uninhabited, UNESCO-listed, and protected as a Costa Rican national park, this 24-square-kilometre volcanic island supports an ecosystem so rich and so isolated that it has been called the "Galápagos of Costa Rica" — though many divers would argue the comparison flatters the Galápagos.
The island's terrestrial landscape is a vision of primordial tropical wilderness. Dense cloud forest covers the interior, its canopy dripping with moisture gathered from the constant trade winds. Over seventy species of vascular plants are found nowhere else on Earth, and the interior waterfalls — some plunging directly into the ocean from cliff faces hundreds of metres high — create scenes of such cinematic beauty that Steven Spielberg used the island as inspiration for Jurassic Park's fictional Isla Nublar.
But it is beneath the surface that Cocos Island achieves its greatest renown. The underwater seamounts and cleaning stations around the island attract marine life in concentrations that stagger even experienced divers. Scalloped hammerhead sharks gather in schools numbering in the hundreds — a sight so extraordinary that many divers return to Cocos year after year pursuing the perfect hammerhead encounter. Whale sharks, giant manta rays, silky sharks, whitetip reef sharks, and enormous schools of yellowfin tuna patrol the waters, creating an underwater spectacle of almost overwhelming intensity.
The diving sites around Cocos are legendary. Bajo Alcyone, a submerged seamount, is the premier hammerhead cleaning station. Dirty Rock delivers encounters with marble rays, eagle rays, and the occasional tiger shark. Manuelita Island, just offshore, offers a more sheltered dive where whitetip reef sharks carpet the sandy bottom in remarkable numbers. Night dives reveal a different world entirely — hunting whitetips, octopuses, and bioluminescent organisms creating an underwater light show.
Cocos Island is reached exclusively by liveaboard dive vessels departing from Puntarenas, Costa Rica — a 30-to-36-hour open ocean crossing that serves as both journey and filter, ensuring that those who arrive are genuinely committed to the experience. Trips typically run seven to ten days, with multiple daily dives. The island is diveable year-round, though June through December offers the best chance of hammerhead encounters and whale shark sightings. Non-divers are not well served — there are no beaches suitable for swimming, and landing on the island requires park permission. For divers, however, Cocos Island is quite simply one of the most extraordinary underwater environments on Earth.