Time seems almost infinite during the 36-hour crossing from mainland Costa Rica to Cocos Island. Every waking moment is spent sunbathing, reading, catching up on missed movies, or daydreaming about what you’ll see tomorrow.

“Most of the divers come to Cocos expecting to see hundreds of schooling hammerheads,” says Jaume “Jim” Pericas, cruise director of Undersea Hunter’s Argo. “Our success rate is about 90 percent.”

For the first six days at Cocos, our group of six divers is in the unlucky 10 percent. It isn’t for lack of trying though. Cocos’ more than two dozen sites are the kind that make Top 10 lists, and we are hitting them all: Dirty Rock, Manuelita, the whitetip shark night dive at Ulloa. Every dive features eagle rays and yellow-lined snapper carpeting the bottom, a few burly Galapagos sharks and a resident tiger shark that apparently loves our group (and not the other). Heck, I even try a 1,000-foot dive on Argo’s über-cool DEEPSEE submersible. I see jellynose fish, a family of frogfish, even a thresher shark. Everything but the hammerheads.

And there is the problem: We become so paralyzed with seeing the schools of hammerheads that we almost fail to appreciate the beauty right in front of us.

If you don’t like Hollywood endings, you can stop reading here. After days of clouds and rain, the sun emerges that final day as we make our way to Alcyone. Halfway to the site, I realize that I’ve forgotten to change my macro setup from the previous day’s night dive. “Not bringing your camera should guarantee we’ll see the sharks,” says Pericas. Mindful of the failed attempt to dive Alcyone only a day before due to strong current, my buddy Mary Anne offers to let me take her video camera down.

I enter first, and am shocked at the ferocity of the current. Hand over hand, I pull myself down the line. At 45 feet, I reach a thermocline that turns the blue water to a turbid green.

At 100 feet, I grab a clump of rocks to steady myself against the current. As barnacles tickle my fingers, I wait for the others to make their way down the line. Thirty seconds later the sharks start appearing — in ones and twos, and finally by the dozens. I start shooting.

The thermocline gives the video a grainy look that makes Zapruder look like an IMAX film, but my eyes don’t lie: I am seeing the schooling hammerheads of Cocos. At one point, I turn off the camera to just marvel in nature as the sun silhouettes the sharks above. As we slowly ascend through the murk, past mammoth schools of mutton snapper and bigeye trevally, one by one we dance a jig of happiness. I am smiling so wide that my mask keeps flooding.

The hardest part of any trip is the leaving — not being home yet with family, and no more diving too. But a trip to Cocos is even harder because of the 36-hour boat ride back to Puntarenas, back to reality. We all find different ways to kill time — sunbathing, reading, looking at videos from the trip — knowing it will all be over tomorrow. That there’s no more searching for the sharks of Cocos Island.

Read more in our Ultimate Diver's Guide to Live-Aboards and find out how you can experience Argo.

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