Things to do · Destination Guide
Remote Pacific liveaboard diving where hammerheads gather around volcanic pinnacles
Pick an activity mode to compare signature sites, skill fit, and gear planning notes before you lock your trip.
Sea Hunter and Aggressor expedition skiffs reach remote diving around Manuelita, Dirty Rock and Alcyone, where volcanic relief, cleaning stations and current attract reef sharks, schooling hammerheads, rays and fish. This is an advanced open-ocean expedition rather than resort diving. Diving is park-regulated, normally in daylight, and specific sites may change with weather and assignment.
Alcyone (Bajo Alcyone)
Submerged volcanic mount with a well-known hammerhead cleaning-station setting; current and depth can be demanding, and sightings depend on the day.
Dirty Rock (Roca Sucia)
Open-water rocky formations associated with schooling scalloped hammerheads, large schools of jacks and rays; conditions can be challenging.
Manuelita Outside
Wall, boulder slope and multiple cleaning stations with reef sharks, rays and seasonal pelagic visitors; swift currents possible.
Manuelita Coral Garden
More protected reef and coral-garden route with fish and whitetip sharks; no longer plan historic night-diving products because the current park activity window ends before dusk.
Chatham Bay
Shallower reef and sand route used for gear checkouts, with smaller reef life and occasional sharks.
Ulloa and Lobster Rock
Rocky reef and rhodolith habitat with reef fish, white-tip shark activity and notable smaller species; depth and current still require evaluation.
Punta Maria
Exposed submerged pinnacle and shark cleaning-station area; the operator chooses it only when park allocation and marine conditions allow.
Big Dos Amigos
Rocky islet with an underwater arch and fish concentrations, sometimes with hammerheads; an exposed site for capable divers.
Operator Checklist
Book a specific confirmed vessel rather than an undated Cocos fleet listing. Sea Hunter has recent 2026 Cocos trip reports and Aggressor publishes active itineraries for Okeanos Aggressor II and Cocos Island Aggressor. Argo is not currently a Cocos option. Reserve Nitrox qualification early if you intend to use it; Sea Hunter includes Nitrox fills, while Aggressor lists it as an extra. Verify the boat's depth rules, minimum certification, recent diving requirement, park approval, medical form, insurance, computer, SMB and locator equipment. Do not assume night dives or technical profiles are included.
Conditions Fallback
Avoid