Cocos Island

Cocos Island in a Nutshell


Considered one of the world's top dive travel destinations for big animals, Cocos is most famous for schooling hammerheads. There are lots of other sharks too, as well as large marble rays, mantas, whale sharks, and schools of fish.


Cocos Island Intro


Cocos island offers the diver big animals, open ocean, and advanced diving. Howard Hall's film "Island of the Sharks" was filmed here, and sharks are the main attraction. Cocos is not a place with pretty corals or reefs. It is a gorgeous, uninhabited island, approximately 5 x 2 miles (8 x 3 km) in size. The bottom is a sloping rocky substrate without a lot of color. What you do get is amazing marine life - prolific shark populations including reef whitetip and scalloped hammerheads, plus a chance of many other species. There is also great schooling fish action, and a good chance of seeing true pelagics like wahoo, tuna, and even billfish.

If you are comfortable with deep (100ft) nitrox diving in open oceans, and the possibility of swell, strong currents and low vis, Cocos island can be the apex dive trip of your dive career. It is not a place for non-divers. Cocos island is quite a beautiful island to look at topside, and short excursions to the island are possible, but you are on the boat almost all of the time. The island is lush and green with rainforest and waterfalls. Malpelo island is another destination that Cocos liveaboards sometimes visit during the same trip. It is not that attractive and you can not go ashore.


Cocos Island Typical Dive


On a typical dive, you drop down as a group to a depth of 100ft , spread out and find a rock to hide behind. You then look for a cleaning station for hammerhead sharks, which is often a larger rock with many angelfish and butterflyfish around it.  Hammerhead sharks are easily spooked by erratic divers' flailing limbs and exhaust bubbles. Attempting to approach these sharks usually only leads to their quick retreat. In order to get a chance at a close approach, enabling opportunities for good photographs, quickly and carefully locating a suitable rock to hide behind and controlling your buoyancy and breathing is essential. Divers are advised to become "blue" divers; (holding your breath when the sharks approach). By following the divemaster's directions, calming down, being patient you will greatly improve your chances of close passes and prolonged encounters.

 3 dives a day are the norm at Cocos, with occassional night dives. On several days a night dive will be offered with white-tipped reef sharks. Divers's lights illuminating the fish causes a feeding frenzy with the sharks. Any fish or turtle illuminated by a dive light will be quickly assassinated by several sharks, and because of this, some divers may not enjoy this dive or choose not to do it. On a remote trip like this, you need to pay attention to your depth & time, and follow the divemaster's instructions carefully, and double check your surface market buoy at the beginning of each dive.



Cocos Island Marine Life & Photography Subjects


Hammerhead sharks are drawn to Cocos to be cleaned by King angelfish, butterflyfish and other small fish. These islands are basically giant cleaning stations. Dozens of white-tip sharks are usually seen on every dive at all depths, cruising around the rocks. Enormous schools of bigeyed jacks, barracuda, snappers and grunts are seen on many dives, and the size of these schools must be seen in person to appreciate. Marble rays are very frequently seen in groups of 5-20, feeding on the bottom at 100ft . Marble rays are easy to approach and are always cruising around like they are on parade.

Whale sharks occasionally pass through, and there are often a couple sightings on a trip. Large tuna, mantas, silky and silvertip sharks are often seen as are eagle rays. Orcas, tiger sharks, dolphins, wahoo, and sailfish are also seen but not on every trip. Dolphns and tiger sharks are quite frequently seen, up close. Divers have seen dolphins hunting jacks. Galapagos sharks, which can be aggressive, are not as common, but do sometimes appear.


Incredible Cocos island underwater video showing turtles, eagle rays, huge schools of jacks, whitetip sharks, hammerheads, mantas, and a tiger shark.

More hammerheads, eagle rays, jacks, whale shark, frogfish, and whitetips frenzy feeding at 4:13

Dolphins, hammerheads, and an awesome tiger shark at 2:17

Best Time To Dive Cocos Island


Cocos has a rainy season and a dry season. If you visit the islands in June/July, you may have a chance of having both big animal encounters and calm seas. Dry season is Dec - May, which can bring silky sharks, dolphins and mobulas, calmer waters and smoother crossings. Rainy Season is June - Nov; and crossings can be a little rough, there's a lot of rain, but Hammerhead sharks are in larger numbers. That said, you will usually see good numbers of hammerheads throughout the year. May - Aug are probably the best months to go, but sightings/conditions can be highly variable. Note that hammerhead sharks sometimes go deep during an "El Nino" year.


Cocos Island Water Temperatures


In June/July, the water is sometimes 81 degrees at all depths. It stays from 80-82 during the summer. The water can get much colder, down in the lower 70s in the winter. Thermoclines are common, and deep down can get into the 60s.

Cocos Island Underwater Visibility


In June, July the visibility was 50-70ft. Visibility can be variable but 30-50ft is the norm, with even better visibility from Jan - May.

Getting There


Liveaboards depart from Puntarenas, Costa Rica. The boat will pick you up from San Jose, Costa Rica. Travel time is approximately 40 hours to Cocos, 43 hours to Malpelo, and 40 hours from Cocos to Malpelo. At certain times of the year the crossing can be very rough with big swells and seasick passengers.


Non-Diving Activites in Costa Rica


Costa Rica is one of the top nature destinations in the world. There are excellent opportunities to see monkeys, toucans, brilliantly colored tree frogs, monkeys, toucans, parrots, sloths, and many more birds and animals. The country is small, easy to travel around, and relatively safe. We highly recommend some time exploring the county either before or after your Cocos trip. There are not many non-diving activities at Cocos Island itself.



Reviews (1)

Simi Valley, CA
United States

Cocos Island is my favorite dive destination - I have only had other trips come in second or third but never ahead of this one! We dove with the Undersea Hunter group and they are excellent on all levels. They have three boats for their live aboard operations; The Sea Hunter, Undersea Hunter and the Argo. We stayed on the Undersea Hunter which is the smallest boat and therefore takes a smaller group of people which I prefer. The Argo is the more luxurious vessel and is a very beautiful if you don't mind parting with the extra money. There is also a deep sea submersible that sometimes goes out on the Sea Hunter if there are guests that want the experience of a deeper dive.

Every dive site we went to had something spectacular to see. Besides large schools of hammerheads at sites like Alcyone, we saw silky and galapagos sharks. An added adventure is night diving with schools of white tips on the hunt. There is no end to what you can see at sites like Manuelita (outside) because the currents bring in all sort of pelagic life; several species of rays, whale sharks and tiger sharks. Turtles, sharks and rays continuously circle in the shallows looking for the cleaner fish and it's a treat to watch all the activities. It's amazing what can swim by on an open water drift. We had dolphins, sharks and rays pass us on an early morning safety stop.

Then there are the fish! Not everyday fish either! Cocos is a place where you can see the oddball batfish in relatively shallow water. I found the always busy leather bass fun to watch and photograph. You will also see very large schools of jacks and large predatory fish that the sharks follow in search of food.

The crew on the boat are the best and so is the food. The cabins were comfortable and there were plenty of places to relax on the boat. You will want for nothing on the Undersea Hunter boats!

Visited on 06/2009 - Submitted on 01/19/2014