Why did UNESCO choose Cocos Island National Park as a World Heritage Site? It is the only island in the tropical eastern Pacific, and it provides critical marine habitats — deep waters pumped with nutrients from life-giving currents — for large pelagic fish, including the planet’s biggest — the whale shark — as well as schools of hammerhead sharks, yellowfin tuna and manta rays.

“My first visit to Cocos Island, Costa Rica, was aboard the Okeanos Aggressor in the mid-’90s,” says underwater photo pro Scott Johnson. “Nine return trips have confirmed Cocos is still where the wild things swim, from sharks and massive schools of bigeye jacks to shy red-lipped batfish and plump giant frogfish. Marine life flourishes around the island.”

If you’re addicted to high-adrenaline diving, you’ll satisfy your cravings at sites like Chatham Bay, where you’ll make a night dive and have a ringside seat right above the fray as dozens of frenzied whitetip sharks explode into action just below where the Okeanos Aggressor yachts moor. At the beautiful seamount Submerged Rock you’ll find a swim-through arch that offers a little of everything, from reef fish to pelagics. At the deep, current-swept plateau known as Punta Maria, burly Galapagos sharks gather at cleaning stations.

Okeanos Aggressor guests are shuttled ashore to hike through the jungles of Cocos, swim in the island’s many waterfalls and visit the Ranger Station. The island is famed as the location of one of Jurassic Park’s stunning waterfalls. All trips are 10 days with seven days of diving. Both yachts depart from the port town of Punteranas.

Both the 110-foot Okeanos Aggressor I and 120-foot Okeanos Aggressor II carry 22 passengers in 11 staterooms.

The yachts boast the comforts of home, service of a five-star hotel and expert guides that help make diving dreams come alive.

For more information, visit aggressor.com or call 800-348-2628 to book your trip.