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  • Writer's pictureMiao

Cocos Island, Costa Rica

Extremely exotic and remote, possibly the most storied shark diving site in the world – of staggering wonders and fighting a heartbreaking battle against illegal fishing. For myself and many, an adventure of a lifetime.

Where on Earth

Cocos is a lush, green uninhabited island resting 342 miles off Costa Rica's Pacific coast, only reachable by boat so the only way to dive is via liveaboards.

The Diving

You'll find schooling hammerheads, Galapagos, white tips, black tips, tiger sharks, whale sharks (when you're lucky). Here are my favorites:

Baja Alcyone – many people swear by Alcyone as THE spot to see schooling hanmmerheads. They tend to swim below the thermocline (usually around 30m) so do plan your dive smartly to max out your bottom time. Besides hammerheads, there’re often silky sharks, Galapagos sharks sometimes whale sharks that frequent the cleaning stations. You’ll likely also see a range of rays. No one ever has time for it but there is actually some interesting macros on the reef too, from mating octopi to mottled soapfish.

Dirty Rock - Small volcanic pinnacles rising just above the waves and separated by a sheltered channel –– anyone thinks it looks like a mini Darwin from the Galapagos? Arguably the popular spot at Cocos given its hammer action. This is where we had the best dive of our 10 day liveaboard. The time my panga saw the first massive school of hammerhead, the other panga saw that, AND a whale shark.

Night Dive - Tired of blooming corals and nudibranches? Here's some adrenaline pumping feeding frenzies with a couple hundred reef sharks for a change! All the white tips started to look like little hungry puppies after 2 dives until...

When to go

Despite being close to the Equator, Cocos enjoys comfortable weather with frequent thunderstorms.

Air temperature: 25-26 degrees year round

Water temperature: ~27 degrees, varies very little seasonally but drastically from thermoclines

Best time to go: June – November. This period sees more precipitation and rougher seas, but the upswell brings nutrient rich water (and poor vis) to the surface, attracting more action from mantas and whale sharks. Disclaimer: One of the best dives on my trip was on one of the worst weather days at the island, torrential rain and avalanche and yet there’s never guarantees since I failed to see any manta or whale sharks when I visited in the prime month of September back in 2015!

That said, December – May isn’t a bad time to go either. More sun, calmer seas, better visibility (and deals!)

Dive with: Okeano Aggressors II

One of the first dive operators that go to Cocos, a legend in itself. Almost all of the staff have worked on the boat for the last 10-15 years!


Visited September 2015, Liveaboard.

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