Five hundred kilometres off Costa Rica, Cocos Island's submerged seamounts like Manuelita and Dirty Rock draw scalloped hammerhead schools into the blue during the rainy season on liveaboard circuits from Puntarenas. Whitetip reef sharks carpet the reef at night while hammerheads patrol the morning thermocline. July through September sits at the heart of the most reliable hammerhead weeks.
Five hundred kilometres off Costa Rica, Cocos Island's submerged seamounts like Manuelita and Dirty Rock draw scalloped hammerhead schools into the blue during the rainy season on liveaboard circuits from Puntarenas. Whitetip reef sharks carpet the reef at night while hammerheads patrol the morning thermocline. July through September sits at the heart of the most reliable hammerhead weeks.
Up to 95% sighting chance in Cocos Island (Costa Rica). Best months: July, August, September.
The rainy season from June through December is prime, with July to September offering the most consistent hammerhead schools at seamounts like Manuelita.
Liveaboards depart Puntarenas for 10-day trips costing roughly 3,500 to 5,500 US dollars (2026 prices). The crossing takes about 36 hours each way.
Morning dives along the thermocline above seamounts like Dirty Rock typically produce the strongest hammerhead traffic.
Whitetip reef sharks carpet the reef at night. Galapagos sharks, silky sharks, and occasional tiger sharks share the seamounts with hammerheads.
Advanced open water and experience in current and deep profiles are standard requirements on Cocos liveaboards.
