Finding joy in jaws – diving with sharks

I love the looks on people's faces when I tell them I went scuba diving with hammerhead sharks on my vacation. It's a blank, uncomprehending stare. Eventually, I convince them I'm telling the truth: I did go to "Shark Island" – that's Cocos Island, Costa Rica – and willingly dived into the shark-infested waters.

We saw hundreds of hammerhead sharks. With prehistoric looks, eyes out on the ends of their heads, and a distinctive back-and-forth swimming motion, they seem fierce, yet run like sissies from the schoolyard bully at the sight of divers' bubbles.

The most popular dive site in the area, Alcyon, is an underwater plateau at about 100 feet. It serves as a huge cleaning station for hammerheads – a shark car wash with little fish doing the scrubbing.

Descending the anchor line (the current at this site can be strong), divers perch on the plateau, partially hidden, and watch the show. Sometimes schools of hammerheads continue as far as the eye can see, top to bottom, side to side, and just keep coming. In the rocks that divers cling to, moray eels and octopuses swim almost unnoticed, outdone by the larger creatures swimming by.

After about 20 minutes of admiring the show, it's time for divers to go up again.

For advanced divers only, Cocos is the ultimate in big-creature diving. Located 300 miles southwest of the Pacific coast of the mainland, its remoteness is its salvation. The ocean crossing takes more than 32 hours, and only two dive-boat companies service its protected waters.

Hammerheads aren't the only attraction. This lone isle draws marine life from hundreds of miles around, including many types of sharks, bottle-nosed dolphins, giant manta rays, whales, and thousands of smaller fish in schools. Juvenile whitetip sharks line up as they rest on the bottom, looking like so many 747s. They swim in a graceful, fluid motion, and they're everywhere.

I was afraid only once: While snorkeling with a pod of dolphins, silky sharks charged us. Sharks don't usually go after divers, but they do feed near the surface, which is where you are as a snorkeler. When I saw a silky swimming toward me with a mean look in his eye, I swam as fast as I could back toward the boat, kicking and splashing all the way. I saw "Jaws," and I know you're not supposed to splash – but terror took over.

Dive master Hugo told me to take it slowly. I didn't get out of the water because I wouldn't leave the dolphins, which pushed the shark away from me. With their protection, I felt safe enough to stay in the water and enjoy their antics. The happiest-seeming creatures on earth, they kept swooping by with those gentle, intelligent eyes. Knowing that they could swim away at any time, but they chose to stay and play, gave me an indescribable feeling.

For 11 days, we lived on a comfortable dive boat, The Sea Hunter, with 20 divers and seven crew, and never touched dry land. We had seven full days of diving, with three dives a day. The chef and his stewards created food sculptures that resembled sea creatures – a hammerhead out of bread dough, for instance, and whales carved from eggplant.

Anchored in one of several natural harbors of the exotic isle, the boat bobbed gently as we marveled at the rugged terrain of the volcanic island with its vine-covered rain forest and ribbony waterfalls falling from steep cliffs. Frigate birds, terns, and black-footed boobies filled the sky. Now a national park inhabited by only a handful of rotating park personnel, Cocos's legend has it that pirates buried their treasures here in the 17th and 18th centuries.

On our last day of diving, we received a "gift" at Alcyon: Two giant manta rays with 12-foot wing spans appeared, soaring around our group like birds. It was breathtaking.

In addition to the sense of adventure, diving with sharks fosters a love and respect for these creatures – which generally seem only too happy to share their ocean, if we humans are alert and follow their rules.