Sea Hunter, Cocos Island, Costa Rica

Dear Fellow Diver:

I descended to the bottom, where everything was dark except what my flashlight illuminated. Suddenly, a barberfish (a.k.a. blacknosed butterflyfish) sped by, swimming for its life, as a white-tip reef shark chased it down. The white-tip, a nocturnal hunter, maneuvered more quickly than I expected, and within seconds, it caught and devoured the barberfish. A dozen other white-tips sped about, looking for meals of their own. I caught up with the rest of my dive group, and minutes later, a ten-foot-long, heavy-bodied Galapagos shark circled us a couple of times. While this might be the beginning of a neophyte's nightmare, it was exactly why I returned to dive remote Cocos Island.

My trip began in early January with an overnight in Costa Rica's capital city of San José, then a comfortable two-hour shuttle ride to the port in Puntarenas, with the garrulous driver, Rudy, relaying anecdotes and pointing out different species of trees along the way. After boarding the M/V Sea Hunter and receiving an orientation and safety briefing, we began our 36-hour steam to Cocos Island. I had plenty of time to set up my dive gear, and while it takes me a couple days to get my sea legs, even on calm crossings while wearing a Scopolamine patch, I spent a lot of time lying down. I just wish my mattress was more comfortable.

Upon arrival, I joined the checkout dive in the protected waters of Chatham Bay, where I saw a huge female sea turtle and some white-tips, but no large sharks. It was different two hours later at Manuelita Outside, where, besides more white-tips, several scalloped hammerheads, a tiger shark and a Galapagos shark or two passed by. And this was only my second dive! Divemasters stay with the group throughout the entire dive, pointing out interesting creatures and sharks approaching from the distance; they are there if you need them but are not overbearing. On calmer dives, our group would disperse a bit, with buddy teams moving apart from one another to better see the wildlife.

Divers make this long trip to swim with sharks. On some dives it's just a couple of white-tips, but most times there will be more. For example, I descended the mooring line at Alcyone and joined other divers atop the sea mount to watch at least a score of scalloped hammerheads come in to be cleaned by barberfish and occasionally a king angelfish. They remained at a distance, wary of so many bubbles. After waiting 15 minutes in chilly 72-degree water (it was 81 degrees above the thermocline), divemaster Mauricio ("Mau") motioned us to begin our ascent. Suddenly, 45 feet off the seamount, just at the edge of visibility, I saw the much-sought-after "wall of hammerheads," consisting of at least 100 sharks.

After a 15-minute panga ride, I was back aboard the Sea Hunter, drying off with one of the large towels provided after every dive, then I headed inside for their hot pizza lunch. One will not go hungry with the Undersea Hunter Group; they offer plenty of dishes at their buffets. Lunch and dinner entrees are warm (no cold, white-bread sandwiches here), fresh fruit was always available, and green salads were piled with toppings like avocado, tomatoes and hearts of palm. Meal options included huge portions of grilled steaks, chicken and sustainably-raised/caught fish. I let the boat know ahead of time that I was a vegetarian, and they provided plenty of fresh vegetables (sautéed zucchini, carrots, buttered potatoes and more), and even made me soy meat substitutes so I was able to enjoy a burger for lunch with the rest of the crowd. Desserts included freshly-baked tres leches cake and ice cream sundaes. Cookies, crackers and fresh fruit were available around the clock, as were sodas and beer.

My two previous trips to Cocos Island were on the MV Argo, another of the Undersea Hunter Group fleet, to assist biologists in tagging turtles and sharks. I made four dives per day on those trips, but on this one, I was disappointed that we were only doing three dives on most days, plus a fourth dive on two nights. Divemaster Federico explained that three dives is usual for regular Undersea Hunter Fleet trips, but the biologists run four dives when they charter the Argo. So I used my additional free time to process photos, read, nap and watch movies from the boat's DVD collection on the large flat-screen TV in the lounge.

This trip, 20 guests -- five women and 15 men -- filled the 10 cabins. There were Americans, Germans, French, Israelis and a single Brit, ranging from late 20s through age 60. Everyone spoke passable, if not fluent English, and the crew communicated in English. I was traveling with my spouse and four friends, so we tended to eat and hang out together. Four of the other guests were traveling alone, and each would sit at different tables during meals to get to know the others. When not working, the crew typically kept to their quarters. It was a friendly crowd, though two guys, perhaps a bit lonely, would often start chatting as I was reading or watching a movie. Toward the end of the cruise, the crew treated us to a wine and cheese happy hour as they hawked t-shirts and other merchandise. Then Mau did several magic tricks and one guests told some pretty good jokes, which added to the camaraderie.

At 130 feet, Argo is the largest of the fleet, but because the stern is devoted to carrying a submarine, it has less room for divers than the nextbiggest boat, the 115-foot Sea Hunter. Its larger dive deck and lounge make it more comfortable, even though it carries two more passengers than the Argo does). The camera area is better situated on the Sea Hunter, where it is out of the way of traffic. On both boats, the cubbyholes are large enough even for housed DSLRs and accessories, and there is plentiful 110- and 220-volt power. Two dedicated rinse tanks sit toward the rear of the dive platforms, and there are two post-dive hot showers. All three of the Undersea Hunter's fleet (the Undersea Hunter is the oldest and smallest of the fleet) make regular trips to Cocos, although it's the Argo that is chartered for research or filming crews. I enjoyed stories our divemasters told about when, say, Howard and Michele Hall or Sylvia Earle was aboard.

My days started with a 7 a.m. breakfast that varied from day to day. In addition to plenty of fresh fruit and toast, they cooked up eggs (sometimes scrambled, sometimes over-easy), pancakes, bacon and "Gallo Pinto," the Costa Rican specialty of rice and beans. An hour later, I headed off for the first dive of the day. They split us 20 divers between the two 24-foot covered pangas, with one divemaster each (we left our gear and tanks onboard between dives and at night). The pangas are just large enough for each diver to sit in the center and don/doff gear. At the back of the pangas is an easy-to-climb ladder, and the drivers would always help me with my gear when entering or exiting.

Backrolling into 81-degree water, I descended the mooring line at Punta Maria, one of more than a dozen sites. The current was so strong that if I let go the line, I would have been unable to make my way back and would have had to surface for pickup. But it's these currents that bring the big guys. When I arrived at the seamount at 93 feet, several large Galapagos sharks were hanging at a cleaning station. But at my next dive, at Punta Maria, there was virtually no current, and therefore, no big sharks. As with most dive sites around Cocos, it was teeming with reef life -- a variety of morays, marbled rays with wingspans as wide as my outstretched arms, Mexican goatfish, blue and gold snappers, puffers, trumpetfish and the omnipresent white-tip sharks. Several times I encountered a school of hundreds (or maybe thousands) of big-eye trevally; once I swam into the middle of the school and the fish closed around me so that I couldn't see anything else. By the way, the bottom is composed largely of boulders and rocks, most dotted with dull, brown hard coral and an occasional gorgonian. At Small Dos Amigos, it's just a lot of barnacle-encrusted rocks.

Cocos Island itself is enshrouded in lush greenery. Five miles long by two miles wide, it rises almost straight out of the ocean to an 1,800- foot peak. Its only inhabitants are a group of rangers and a few volunteers; divers can hike on the island once or twice during their trip, but you'll give up at least one dive. I went ashore on a previous trip and was startled by the Genius River Bridge, built by Costa Rican artist "Pancho" out of miles and miles of discarded fishing gear.

Daytime temperatures topside are usually in the 80s. Cocos averages more than 20 feet of rain per year, so it was no surprise to see it coming down as I geared up for my second of two night dives. Although it was only a five-minute ride to Ulloa, I was soaked and chilly in my 5mm wetsuit when we arrived. The 79-degree water felt comfortable in comparison. Moreover, all thoughts of weather left my head when I saw the hunting white-tip sharks. They gathered in schools of 20, 50, or more -- it was hard to tell because I could only see the animals that were in the beam of my flashlight. At times, it looked as though the sea floor was moving, there were so many sharks. They wriggled in and out of crevices, looking for a meal. And when they found one, all the nearby sharks joined in, ignoring the divers hovering above. It's completely crazy -- and completely exhilarating. Forty-five minutes later, Federico gave us the signal to ascend; because we were only in 15 feet of water, there was no need for a safety stop.

Dinner was waiting upon returning to the boat. I filled up on spaghetti (with choice of vegetarian or meat sauce), fresh green salad and garlic bread. Finally, it was time for a well-deserved rest. The Sea Hunter has eight cabins below deck and two on the upper deck. My spouse and I shared the smaller of the two upper cabins, but it was spacious with its double bed (and room to add a bunk, should cabin mates choose to sleep separately), desk and ample storage space. Each cabin has a toilet, sink and curtained stall shower with plenty of hot water.

While it was easy living on board, some dives gave me quite a challenge. At Big Dos Amigos, my dive buddy and I were at 80 feet and reached the beautiful arch before the others. Moments later, the current kicked up, and the rest of the group had to pull themselves along the rocks to reach the arch. None of us could exit the far side due to the current, so we returned the way we came.

As you can probably tell, diving Cocos is not without risks. Half my dives were in the 95- to 105-foot range, and they might have been deeper had all divers not been on Nitrox. Slow ascents, a strict no-deco policy and a maximum 60-minute dive time are enforced. Even so, accidents do happen. On our second-to-last day of diving, the conditions were good so the captain took the Sea Hunter to anchor at the south end of the island. Our group headed for Shark Fin Rock, a rarely diveable site due to waves and strong currents, but today the seas were calm and the current mild. Scalloped hammerheads cruised by in twos and threes, a yellowfin tuna appeared, and I lost track of the number of eagle rays at 12. After returning to the boat, the second panga hastily arrived from the dive at Alcyone with an injured diver. The crew had him on oxygen and brought him on board; the captain quickly contacted DAN. The injured diver was a middle-aged Israeli man. He was unable to urinate but a fellow passenger, who happened to be a physician, catheterized him. It sounded like a central nervous system oxygen toxicity hit because the man was also unable to walk (we were not given much information about him -- a patient confidentiality thing, I suppose). The boat headed toward the mainland, 36 hours away, while DAN arranged for a fast boat to meet us en route 22 hours later and take the patient to shore. The crew then turned their attention back to us, and headed to Caño Island on Costa Rica's Osa Peninsula for three final dives. (And Undersea Hunter Group gave each of its passengers a $500 credit towards a future trip).

Cocos Island is a wild place, 300 miles from civilization. I've seen more sharks on any one dive here than I've seen in weeks on Caribbean and Indonesian trips. This has to be what the oceans looked like a century ago, before humans started decimating shark populations. I've already booked my return trip.

-- S.L.

Divers Compass: My ten-day trip was $5,885 per person, double occupancy, and lower deck cabins cost $5,235; additional charges included a $245 national park fee and $60 for transportation . . . Crew said, "You can tip whatever you feel appropriate," so we tipped $500 each, roughly 10 percent; a credit card is OK . . . Crossings can be rough, so make sure to bring seasickness meds . . . Ask the shuttle driver to stop at the local grocery store before boarding the boat if you would like to buy hard alcohol for the trip, as there is none onboard; wine is available with meals for a charge . . . U.S. plugs/voltage are available throughout the boat, there is also 220-watt power in the camera stations . . . If the Argo is at Cocos, you may have the chance to go on a submarine ride; it's expensive, but worth it . . . Bring gloves, as you may need to hold on to barnacle-encrusted mooring lines and rocks; also bring walking shoes, sunscreen, and bug spray if you plan to visit the island . . . DAN insurance is essential in case of a medical emergency; and bring your C-card or Nitrox card . . . Website: Undersea Hunter Group -- www.underseahunter.com