fter an overnight journey of 375 miles in the Pacific Ocean, 21 lucky divers arrive at one of the most coveted dive destinations in the world, Cocos Island, Costa Rica. A week later, they return to civilization with memories of swimming with hundreds of hammerhead sharks, photographing graceful mantas and splashing in waterfalls on one of the world's largest uninhabited islands.

The 120-foot Okeanos Aggressor, which hosted a Dateline NBC crew filming a "Thrill Seeker" program, offers ten-day and nine-day dive adventures originating in Puntarenas, a small fishing village on the western coast of Costa Rica. After an overnight stay in San Jose, Costa Rica, Aggressor guest board a charter bus for a scenic, two-hour bus ride through Costa Rica's beautiful countryside before arriving at the Okeanos Aggressor port. Once on board, guests may unpack, relax and enjoy delicious dinner served by the on-board chef. The 36-hour journey to Cocos gives everyone a chance to prepare their gear and get to know one another; it also adds to excitement of what lies ahead.

Throughout the week of diving, you'll encounter a spectacular array of marine life large and small-most quite large! Many diver describe the diving at Cocos as "high-voltage" or "on-the-edge," and after drift dives at Alcyone or Big Dos Amigos with a few hundred hammerheads, thousands of horse-eye jacks and a manta or two, you may agree. Other frequently seen marine life includes dolphins, tuna, marble rays, eels, white tip sharks and silky sharks. Okeanos Aggressor divers have also been treated to spectacular whale shark encounters. Weather permitting, guests will be shuttled to the island for a hiking tour. The lush uninhabited island in covered with verdant jungles and countless waterfalls all waiting your exploration. You may want to capture some of the Cocos's underwater splendor on film with one of the on-board rental underwater cameras. There is a full line of rental camera equipment and dive gear available throughout the week, as well as certification and specialty courses including nitrox certification.

At the end of your exciting adventure, the Okeanos Aggressor returns to Puntarenas. Check-out is between 7:00 and 7:30 a.m. On the day of departure, the crew will transport you and your luggage with the group to your hotel, or the airport in San Jose. Due to cooler water temperatures and strong currents, the diving conditions in Cocos may not be suitable for beginner divers.