Revealing Cocos Island's Wild Side Aboard Okeanos Aggressor II Liveaboard
The crossing can be bumpy in October, but that’s your best chance for hammerhead aggregations
Edwar Herreno
Lovely, remote Isla del Coco — as the Costa Ricans call it — is renowned for aggregations of hammerheads so large, they blot out the sun.
But what about an encounter with a single animal big enough to do the same?
We had barely dropped in at Dirty Rock, one of the best-known dive sites at an island famed as the location of one of Jurassic Park’s stunning waterfalls. (Not so the rest of the film: Cocos — as this collection of islets is known to English speakers — is a national park and UNESCO World Heritage site, and much too well-protected to risk anything like a Hollywood film crew tramping about.) Dirty Rock is an open-ocean site; Cocos is a 36-hour ride, or about 350 miles, from the port of Puntarenas, Costa Rica, aboard comfortable, spacious Okeanos Aggressor II. That perfectly positions you to catch a glimpse of anything else moving around out here in the tropical eastern Pacific, from sharks to tunas to manta rays to the biggest “get” of all.
Peering past the rock, I see my dive buddy hanging in the blue. She begins to quiver. Then she’s waving her arms. And then I see spots. Trick of the light, I think. But it’s for real: Expanding — and expanding and expanding — until it fills our horizon is a 30-foot whale shark, cruising serenely over seven ecstatic divers fist-pumping madly and cheering into our regs. It heads for the rock, veering away at the last minute with a flick of its gargantuan tail.
After that, everything else — from hammers to tiger sharks to too many coastal waterfalls to count — is gravy, including actual gravy at Chef Jairol Hernandez’s “Thanksgiving” dinner, a tradition on almost all Aggressor yachts. From its seasoned crew that puts safety first and fun a close second, led by mischievous Capt. Mauricio Marin Cajina, to its totally renovated cabins and spacious dive deck, the only thing you’ll dislike about a voyage aboard Okeanos Aggressor II is when they tell you it’s time to go home.
Look for Commerson’s frogfish on the Chatham Bay mooring-line block
Andrew Sallmon
Trip Itinerary
Day 4: Chatham Bay Night Dive Take a ringside seat right above the fray as dozens of frenzied whitetips explode into action just 15 feet below you in this shallow bay where Okeanos Aggressor II often moors.
Day 5: Submerged Rock This beautiful seamount with a swim-through arch offers a little of everything, from reef fish to pelagics. Currents can be stiff, but when they abate and the sun shines on the mount, it’s magical.
Day 6: Manuelita Deep “I know the tiger shark is here,” says Capt. Cajina, and he’s not wrong: A 13-footer sticks with us for nearly 20 minutes, making pass after pass, a close encounter of the Cocos kind.
Day 8: Punta Maria It’s a 110-foot descent in ripping current to the edge of this plateau, where you’ll cling by your fingertips. Why? To spy on a half-dozen or more giant Galapagos sharks at cleaning stations.
The Okeanos Aggressor II
Courtesy Aggressor
THE BOAT: Okeanos Aggressor II
Total passengers: 22
Cabins: 11
Total crew: 9
Length: 120 feet
Beam: 27 feet
Number of decks: 3
Sights to Behold
Here are a few of the amazing marine species you may see around Cocos
Whale Shark
The biggest fish in the sea — up to 40 feet — is not an uncommon visitor at Cocos’ dive sites like Manuelita Deep, Dirty Rock, Alcyone and Viking Rock.
iStockphoto
Marbled Ray
You’ll see eagle rays on every dive, but Cocos is justifiably famed for another frequently sighted relative of the stingray: huge, brown marbled rays the size of area rugs.
Waterframe/Alamy
Tuna
If you’re more familiar with Thunnus albacares on a plate than underwater, a Cocos encounter might change your habits. Huge and powerful, these intensely focused predators will take your breath away.
iStockphoto
Devil Ray
“Manta!” we thought on one Manuelita Deep dive, but it was something even cooler and more rare: a single, small brown sicklefin devil ray. Check that off the bucket list.
Luis Lamar/National Geographic Creative
Want more thrilling adventures? Check out our picks for the best big-animal encounters for divers.