Destination Fact File
If you like high adrenaline diving, you will be hard pushed to beat this place.
Situated in the Golden Triangle, 550 km off the mainland of Costa Rica, the converging nutrient-rich currents from nearby deep water attract multitudes of pelagic action to Cocos. The Golden Triangle often referred to as the “Golden Hammerhead Triangle”, includes Cocos Island, the Northern Galapagos Islands of Wolf and Darwin and Malpelo (belonging to Columbia). It is so-called because of the hundreds of Hammerhead Sharks and other pelagics. The uninhabited island has around 20 dive sites all in a compact location, from shallow but steep vertical walls, drift diving, to deep pinnacles down to over 40m and blue water diving. All sites are close to the island and one another making Cocos Island an ideal liveaboard diver's playground.
The only way to get around Cocos Island is by liveaboard. Depending on conditions at sea, the boat trip from the Costa Rican mainland usually takes about 36 hours cruise time. So you will have more than enough time to get to know your fellow divers and prepare your equipment as well as catch up on any R&R you may need before your diving at Cocos begins.
Declared a marine national park, the “Isla del Coco” is a large uprising of volcanic seamounts covered with untamed and uninhabited tropical rainforest featured in breathtaking scenes in the movie 'Jurassic Park'. The eco-system has been largely untouched by humans, offering us a rare glimpse into a world where nature reigns supreme, allowing the marine and island creatures to interact undisturbed and thrive in the process.
The main attraction of Cocos Island diving is scalloped hammerhead sharks. You will witness wave after wave of huge groups of hammerheads, some numbering in their hundreds! But there are other regular shark species encounters too; most notably white-tip, Galapagos, silky, tiger, black-tip, silver-tip and guitar sharks. They are joined by many different species of rays including mobula, marble, manta and eagle rays swirling around you in search of cleaning stations.
Moray eels are very visible as they weave and sway from every available crevice in the sheer volcanic wall. Cracks in the wall are filled with smaller fish hiding from the shoals of jacks, who in turn attract a bevy of white-tip reef sharks.
Top Dive Sites:
“Bajo Alcyone” - unparalleled as the place to see hammerhead sharks. After a quick descent to the seamount top at 25m, find a crevice to wedge into and the hammerheads will gently glide into the picture until they fill your entire field of vision! From viewing their distinct hammerhead silhouettes at the surface to watching them descend below you, you will be spoilt for choice with photo opportunities.
The hammerhead sharks prefer swimming below the thermocline which often tempts Cocos divers to descend below 30m. The depth of the dive, coupled with the exposure to rough seas and often strong currents, makes it advisable for you to be an advanced diver to enjoy the many advantages of this Cocos Island dive site.
Due to its offshore location about 1½ km from the island, you will find incredible pelagic action at this spot promising you numerous fulfilling interactions with mobula, manta and eagle rays. Shark cleaning stations thrive with many satisfied customers among the silky sharks and Galapagos sharks, majestic whale sharks are also frequent visitors. At Bajo Alcyone you will be spoilt, not only with shark numbers but also variety.
There is also some life on the reef too, if you can tear your attention away from the shark action. The rocks are home to many octopus and they can often be caught in their affectionate mating ritual, as if aware that your attention mainly lies elsewhere. The crevices are also home to the rather bizarre mottled soapfish, which lie flank down on the sand as if pretending to be dead. As you ascend into the blue for your safety stop you are likely to be accompanied by schools of jacks and the occasional yellowfin tuna. This site needs to be dived to be believed!
The best hammerhead sightings for Cocos Island diving have been reported in the rainy season when rough seas can occasionally make diving impossible. However, the weather is changeable with many a sunny day in between the torrential rains, making the site accessible all year round and your perseverance will always be rewarded, in the most spectacular manner.
“Dirty Rock” - Made up of volcanic boulders and rock pinnacles rising just above the waves and separated by a sheltered 100m channel, this site is the most popular spot for diving at Cocos Island due to the sheer volume of hammerhead sharks and the incredible bio-mass of fish that congregate here.
Your quick descent to 20-25m gets you right to where all the action takes place with hammerhead sharks being surrounded by attentive barberfish. All you need to do is watch the magnificent show as it unfolds around you. Hammerheads and marble rays will swim right up to you; around, above and below you. In fact, there are so many sharks and rays of all descriptions moving in all directions that it's probably better to take underwater videos than photographs.
Masses of large reef fish such as leather bass and amarillo snapper sway idly in the surge whilst other smaller snapper species and goatfish harbour in the rock crevices. Large shoals of bigeye jacks, bluefin trevally, hunting tuna and black-tip sharks swerve around the boulders and up into the blue and the occasional whale shark will elegantly cruise into the channel just to make your day.
Gently ascending along the spectacular rock formations brings you into contact with green and hawksbill turtles foraging in the coral. Divers taking safety stops here are often joined by groups of playful bottlenose dolphins. In fact, this is one of the most dynamic Cocos Island dive sites with probably the best all star line up you could find anywhere in the world! You can dive Dirty Rock at any time of year. On a Cocos liveaboard cruise you will get the chance to dive this site more than twice and still want to come back for more big fish interactions.
“Everest” - this is a Deep See Submersible Cocos dive operated by Undersea Hunter Group. DeepSee submarine trips can be booked in advance via the Undersea Hunter office or sometimes at Cocos, subject to availability. The DeepSee Submersible is a custom-built, one-atmosphere submarine capable of carrying one pilot and two passengers to a depth of 475m. This is a once in a lifetime dive and is highly recommendable!
Once you've been towed out to the descent point just off Manuelita Island, you'll begin your descent at about 10m per minute. No need to equalise as you go down, just sit back and enjoy the ride. Once you near the ocean floor at 90m, you'll attain neutral buoyancy and then slowly move towards Everest over the sandy sea bed. The process of attaining buoyancy requires the use of compressed air. When excess air is jettisoned, it bursts towards the surface and this attracts mobula rays that swoop overhead, seeming to delight in the sensation of bubbles on their underbellies.
Usually daylight penetrates this deep, but sub-lights will lead the way to help you find some of the deep water benthic creatures such as the prevalent red-lipped Cocos batfish. The seamoth-type creature hops around on modified 'fin legs' and is unmistakable once you've spotted one. Other creatures you might see here include crabs, snake eels and flounders. But don't focus too much attention on the sea floor as most of the spectacular sightings will be overhead. Small schools of skipjack tuna and scores of Hammerhead sharks will swim slowly above, perfectly silhouetted by the brighter sea surface.
Gradually, the volcanic mountain will loom up ahead. Visibility is pretty good this far down in the ocean, and the covering of basket stars and snow-like white octocorals on the lower slopes together with the mountain peak towering menacingly over 40m above, is probably what gives this underwater mountain and Cocos dive site its name. More deep water creatures can be seen such as deep water bigeyes, scythe butterflyfish, cabrilla groupers, and the rather odd looking brotula fish. Examination of the black coral bushes will yield scores of tiny gobies, anthias and moray eels.
As you look up you'll see thousands of creolefish swarming the peak with yellowfin tuna in hot pursuit. Giant marble rays drift effortlessly over the slopes in search of octopus, goliath grouper and Panama graysby lurk behind the slope ridges. As you ascend back into normal recreational depths, familiar normalcy takes over again. Dense groups of schooling fish, such as mullet groupers and big eye trevally and Pacific crevalle jacks are likely to engulf you as you begin to surface. This unique Cocos diving experience is one that will live with you for a very long time.