cocos hammerhead shark

globe th CopyThe incomparable Cocos Island (Isla del Coco) is located in a remote part of the eastern Pacific Ocean, approximately 550 kilometers (342 miles) off the shore of Costa Rica.   It has been designated a UNESCO World Heritage Site.   There are no inhabitants other than Costa Rican Park Rangers.   The island covers only about 24 square kilometers (9 square miles) and is surrounded by deep waters with converging currents.   It is the only island in the eastern Pacific with a tropical rainforest & the terrain, which is extremely mountainous with numerous rivers and streams, has some truly spectacular waterfalls.

Captivating Cocos Island

aerial view of cocos from the north underseahunter AVI

Cocos Island diving .... in brief

This is not a destination for the novice diver nor for the faint of heart.   Cocos is truly a pinnacle experience for the experienced & adventurous diver.

  • sheer pinnacles, towering walls & deep channels
  • upwellings & the thermoclines,  changeable & sometimes raging currents
  • swarms of scalloped hammerheads
  • mantas, mobulas, tuna & dolphins
  • occasionally pilot whales, marlin & sailfish
  • shrimps, eels, frogfish, snappers, jacks, turtles & a variety of colorful tropical fish (lunch for the big guys!)

Primal & pristine island

The island itself, with no human residents, is one of the few remaining untouched paradise islands & it delights visitors with dense rainforests & astounding waterfalls.  When conditions permit,  most liveaboards offer divers the opportunity to visit this lush, primordial isle.

Admittedly, however, your first priority is not a visit to the unique outcropping of land.   You're there for the exhilarating diving.  Also, you want to be a pretty good sailor if you're going to make the 36-hour boat ride from Costa Rica to Cocos Island! 

But, but worry not.   On this part of the voyage you'll be well-entertained & well-prepared by the crew for your unforgettable Cocos adventure.

Drift dives, scintillating shark action, a profusion of fish

Everywhere you dive at Cocos Island, you'll be surrounded by throbbing throngs of marine life & for most divers, the first trip to Cocos is never the last!

The dive sites encircle the island & diving often begins at Manuelita Island, which, on the west, is a fantastic drift dive that features great shark action.   The opposite side of the island is protected from the currents and it harbors an incredible array of Pacific reef fish, including pufferfish, parrotfish, snappers, jacks . . . plus turtles & more.  This site also functions as a cleaning station.

Cocos Destination Page Vertical Insert

Unearthly rock formations, hammerheads & tigers, rays & pelagic fish

At Dirty Rock, a favorite for many Cocos veterans, the rock formations themselves are other-worldly.  It's at this site where you can usually find the vast groups of scalloped hammerheads .... along with snappers, marbled rays & a variety of sharks.

Many divers, on the other hand, feel that the Dos Amigos dive is the most exhilarating, with its (typically) great visibility, its dramatic underwater arch and simply scores of fish & sharks ... and fish & sharks.

To add a new twist, tiger sharks have been frequent visitors over the past few years and sightings are becoming more and more common.

Liveaboards & newly added Costa Rica diving attractions

With no accommodation on the island, liveaboards are the only way to dive Cocos Island and there are 4 excellent vessels to get you there.   There are the two boats in the Undersea Hunter Group:  Argo & Sea Hunter and the two Aggressor boats: the Okeanos Aggressor I, which hosted Dom's first trip to Cocos, way back in 1988 and the Okeanos Aggressor II (formerly the Wind Dancer).

While we rate the Undersea Hunter Group - Sea Hunter & Argo - as quite simply two of the world's top liveaboards .... there's no question that you'll have a fabulous trip regardless of the vessel you choose.  Both fleets, Undersea Hunter and Aggressor, ensure the highest standards of safety, service and diving ... and richly deserve accolades.

The Aggressor vessels have rounded out their Costa Rica diving selection by offering two new destinations:  el Caño Island and Guanacaste & Bat Islands  .... all just a few miles off the west coast of Costa Rica.  You'll find further destination information below ....

Wondering about the Undersea Hunter?   She's joined the Nautilus Explorer and Nautilus Belle Amie and has become the Nautilus Under Sea, exploring Socorro & Guadalupe.  You'll find her in Socorro Liveaboards.

DeepSee submersible ... a wild ride

In additon, Argo is the home base for the high-tech DeepSee submersible.  Custom-built for the Undersea Hunter Group, DeepSee takes a pilot & two passengers to a depth of up to 1,000 feet (305 m) for a joy-ride, film-making or scientific research.

For an "eye-witness" report, read about Dom's trip to Cocos & Malpelo on the Argo & the DeepSee  . . .

DeepSee submersible ... eye-witness report

Choose your Costa Rica diving adventure

Cocos redlipped Batfish smallCocos Island ...  massive schools of hammerheads & silky sharks
This World Heritage Site is the spectacular crown jewel of Costa Rica's many National Parks. The island’s waters explode with life including innumerable white tip reef sharks, schooling hammerheads, dolphins, manta and marbled rays, giant moray eels, sailfish, and of course the occasional whale shark & tiger shark .....  read more ...

Other common encounters are immense schools of jacks and tuna,beautiful silky sharks, silver tips and marlin.  You'll be fascinated by the swirling Creole fish, the ever-present green turtles and the wandering octopus.  Cocos Island is also home to at least 27 endemic fish species including the exotic rosy-lipped batfish.

Macro photographers don't despair.  While this is largely a wide-angle paradise, you'll find some spectacular corals teeming with wonderful critters ... including some of those endemic species !

We've tried to say it in the article above ... but let's put it into the plainest of language.  This is simply one of a small handful of must-do destinations for experienced and adventurous divers.  The experiences of diving with ocean giants at Cocos, Malpelo and in the Galapagos are unparalleled.   And once you've been here the first time, your heart will ache to return again and again.  Be prepared to become a Cocos addict !

Cocos Cano Island reef fish shutterstock 186874469 Copy optEl Caño Island  ...  marine reserve with scads of pelagics
Located off the south pacific coast of Costa Rica in front of the Osa Peninsula. It is one of the most beautiful jewels in the Costa Rican National Park system.   This lush green tropical island is home to resident tropical fish, beautiful colorful corals & sharks, while passing pelagic species are common .....  read more ...

You'll find large numbers of tuna, amberjacks, wahoo, rays & turtles, plus enormous schools of tropical fish.  In the vicinity, often on migration trails, are humpback whales, pilot whales, white tip sharks, black tip sharks, nurse sharks.  Occasional visitors are great hammerheads, whale sharks, marlin and dolphins.

Most of the action at El Caño Island can be seen between 30 - 100 feet with visibility between 50 - 100 feet.  The topography makes for interesting diving with fascinating rock formations, including a popular arch and a cave with resident white tip sharks & energetic tropical fish. The coral gardens are large and healthy with a variety of species in a variety of hues.

Cocos marble ray slider sizeGuanacaste & Bat Islands  .... pelagics, critters & a couple of wrecks
Lying just off the western coast of Costa Rica are the island groups of Guanacaste, Bahia Culebra, the Catalina Islands, the Cuajiniquil and El Jobo plus the Bat Islands in Santa Rosa National Park.  These islands host lots of species of rays, mantas, turtles, sharks, large schools of tropical fish, frogfish and other macro life. .....  read more ...

Large pelagics such as humpback whales, dolphins and other sharks are seen and you'll even have one dive with 2 small wrecks which attract lots of tropical fish.   On all the dives here mobula rays, sting rays, eagle rays and devil rays tend to be common visitors.  Nurse sharks are ubiquitous  ... but in the Murcielago Islands area  (Bat Islands) you have the added excitement of bull sharks and oceanic manta rays.

Several dives include some good critter life and macro opportunities for our photographers ... plus plenty of colorful tropical fish species and plenty of the pelagic varieties.  

The topside scenery is stunning ... with the jungles & rainforests of Costa Rica as a backdrop and glittering white-sand beaches lining the coast.  

Kindle your excitement

190 Cocos tiger dive AggressorThis trip report is from a recent Sea Hunter trip ... an eye-level encounter with a tiger shark as well as the magic of entire trip from start to finish.   
"The 4-meter tiger shark came so close that I was certain it was going to bump into me.   All I could do was hold my breath and wait, trying not to let my heart beat out of my chest  ...  continue reading ...

Time seemed to stop, and all that was left in the universe was me and that tiger. Yes, this is what I came here for: sharks. I guess I just didn’t expect to find such an extreme brush with one of the most aggressive predators on the planet on my very first dive of the trip.

Welcome to Cocos Island.

But let’s start from the beginning: the crossing. The crossing was smooth, with several visits from both bottlenose and spinner dolphins. I finally understand what people mean when they say “spinner dolphins.” The dolphins spin sideways in more of a roll than a spin (they should really call them rolling pin dolphins). Thanks to the bright moon we watched them jump and play and dance and best of all – spin – alongside the bow of the ship.  We cheered when one would jump, which prompted the next one to leap.  They squeaked and chirped in response to our encouragement. What a perfect way to start our journey to Cocos Island.

After that first close encounter with the tiger shark at Manuelita, Punta Maria was the next hottest dive site this trip. The enormous Galapagos sharks there were anything but shy.  About 3 minutes after we hit the bottom, the Galapagos started circling us from both in front and behind – some coming EXTREMELY CLOSE. This delighted the many photographers on our team, who came from Germany for an underwater photo safari. Four, five, then six Galapagos all crisscrossed paths underwater as we watched, took pictures and video. Fine spotted moray eels swam out in the open, like fish.

Day 5, we tried to visit Submerged Rock on the east side of the island, but there was too much current so we headed back to Manuelita Outside. The current there was very strong with waves slamming against the rocks, and the captain was hesitant to drop us there. But Edwar, with 10 years of experience on the island, knew the current would be OK once we descended to the bottom. Just in case, we sent Giovanni (the dive guide in training) ahead as the guinea pig.

After scoping out the conditions and assuring they were safe, we dropped down on top of a couple of hammerheads at the bottom. A sting ray, a couple of big tunas, and HUGE Tiger shark passed by – so big that at first I thought it was a whale shark by the way it slowly ambled through the water.

As we ascended to about 60 feet, I saw a school of what I thought were jacks glittering out in the distance. I adore jacks, so I swam closer. All of the sudden I realized they weren’t jacks at all – this was a wall of hundreds and hundreds of hammerhead sharks. I simply can’t believe fish that big school in numbers so large. They just kept coming, and coming and coming…in droves. They’d disappear for 30 seconds and then return again. The wall was so thick I couldn’t see through it to the other side. If you’ve never seen a wall of hammerheads, breathtaking is the only word to describe it.

Dirty Rock also proved to have some good shark action. My favorite dive there started when we heard dolphins squeaking in the distance. A tuna darted in and out of a big school of jacks, so we knew we were in for a show. All of the sudden I saw a big playful dolphin swim right past me, immediately followed by a muscular black tip reef shark, and then a huge Galapagos with several black jacks in tow. Back at the surface, a gorgeous rainbow awaited us just before dinner.

The night dives at Manuelita were spectacular, as usual, with a bit of a surprise visit one night from an enormous Galapagos shark. Usually white tips have the run of the reef at night, but on this occasion the Galapagos arrived about halfway through the dive and tried to nab itself a white tip for dinner. Luckily for the white tip, the Galapagos missed its target – however the bigger shark’s presence spooked pretty much all of the smaller white tips. The Galapagos spent the rest of the dive swimming circles around us, looking for white tip prey. We felt lucky to witness such unusual shark behavior.

The last day, the sun was shining so we kayaked from the Sea Hunter ship to Chatham bay – which took about 7 minutes of leisurely paddling. Gliding over the reef, the water was so clear we could see at least 100 feet down to the bottom. We drifted ashore and visited a waterfall, then we climbed over rocks etched with historical names – like the infamous pirate Captain Morgan and revered underwater explorer Jacques Cousteau. My favorite part of the island jaunt was watching the adorable little baby black tip sharks surfing the teeny tiny shallow-water waves in the bay.

The crossing on the way home was easy, with water so smooth it seemed unreal – the ocean undulated like a vat of poured oil. Since we were running ahead of schedule, we stopped on the way home for a quick swim in the clean, crystal-clear sea: a truly perfect end to a perfect trip


INFO symbol CopyTravel, Weather, When to Go  ... All the practical info you want to know before you go

how to get there  ...  best time to go  ...  weather   ...   water temperatures   ...   diving condition  ...  immigration & visas   ...   what to bring  ... insurance requirements   ...   and more

Cocos Know Before You Go


Searching for a
new diving mecca ?

Indonesia Komodo National Park Islands Water Green

Cuba
Oman
Bikini Atoll

Bimini, Bahamas
Roatan, Honduras

See New Destinations

Pump up your adrenaline
with shark encounters

Whale shark clear water feeding shutterstock 184425674

Cocos & Galapagos
Tiger Beach, Bahamas
Cat Island, Bahamas
Guadalupe Great Whites
+ more ...

See Shark Encounters

Time for a
unique adventure ?

Philippines Plane Wreck Diver Floating

Antarctic peninsula
Lake Baikal, Russia
Far North Great Barrier Reef
Sardine Run, Africa
+ more ...

See Special Expeditions