10 live-aboard dive adventures

ADVENTURE HEAVEN
Coco Island, Costa Rica — Okeanos Aggressor

The mainland is 375 miles away, but after the long ride over from Puntarenas in Costa Rica, it feels like you’re a million miles from the nearest civilization. The mysterious, jungle-covered island looks like something straight out of the Jurassic, which is fitting since the hammerhead sharks schooling below the boat have scarcely changed since then.

Ty Sawyer / Sport Diver

I’ve seen a lot of sharks over the years, but hammerheads still fascinate me — and make me a little nervous. There is something ... alien about that flattened head and wide-set eyes. Plus, you can’t help but notice the mouth with abundant teeth underneath the weird face. One of the great memories of Coco is looking up and seeing dozens, even hundreds, of scalloped hammerheads between you and the surface.

Hammerheads may be the specialty, but they are not the only item on the Okeanos Aggressor dive menu. Up close, a giant manta is even stranger and more magnificent than a hammerhead. Somehow they always look to me as if they’d be as comfortable in outer space as they are in the ocean. At night off the lee side of Manuelita Island, hundreds of small whitetips gather in packs to hunt. It’s one of the most unbelievable and memorable sites you’re ever likely to dive.

Sometimes it seems that every creature here comes in packs. Marbled rays roam the reef in such numbers that after a few dives you cease to ogle in fascination. Jacks and snapper school by the hundreds. Whale sharks frequent the open waters, as do silvertips and bull sharks. If you’re lucky, you’ll get the chance to drop in on a bait ball to watch as pelagic billfish, sharks, skydiving sea birds and enterprising sea lions pick the ball apart to the very last oily scale.

Like the other boats in the Aggressor fleet, the Okeanos Aggressor dishes out some great meals. Too bad diving seems to burn so few calories — if I come out even weight-wise at the end of the week, I consider it a victory. Besides the good food, though, I’m always struck by the hand motions at dinner. Divers are as bad as fighter pilots when it comes to replaying the day’s adventures with their hands.

The Okeanos Aggressor offers nitrox as an alternate breathing gas, and I always take that option. Like most divers I use it with an air computer for a greater margin of safety against DCS rather than for extended bottom time. Rebreather divers are also welcome on the Okeanos Aggressor, and that’s a tempting alternative. Bottom time and stealth!

If you’re at all worried about the limitations of visiting a single island on a dive trip, don’t be. The Okeanos Aggressor has dive sites all around Coco, including dozens of small islands, rocks and seamounts. There’s plenty of diversity in depth, profile and sea life. Diving is done from the two custom 22-foot dive dinghies. The surface chop, currents and surge can be somewhat challenging, so come prepared for more rigorous conditions than some other destinations — and bring enough neoprene to stay warm. I like the layered approach because the temperature can vary from day to day and even from dive to dive. In this part of the world, I generally start with a hooded vest and add layers as needed.

MUST DO: SHOWER UNDER A WATERFALL

Almost every trip includes a land excursion down a narrow, fern-choked path to a Jurassic-looking waterfall, where you can swim right up to the base of the falls.

MUST DIVE

1. Manuelita (night dive, too)
2. Dirty Rock
3. Alcyone
4. Pyramid
5. Bajo Dos Amigos

FOR MORE INFORMATION
The Okeanos Aggressor; 800-348-2628;

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