Yucatek Divers, Playa del Carmen, Mexico

Dear Fellow Diver:

"Go, go, go! Over there! Over there!" Several miles off Isla de Mujeres, our guide was yelling and pointing to an immense spotted dorsal fin flopped over on the surface, and a two-foot high caudal fin trailing it by a good eight feet. I went over there, as fast as I could. The shark pulled away easily, finning languid "s" patterns in the plankton-rich water. I clamped down on my snorkel and swam harder, or maybe the shark slowed, but I saw a gray shape in front of me, then the white spots, and then . . .

Whale sharks. For me, they're the Mount Everest of sea beasts, and like Ahab, I've looked for them in the seven seas. In Papua New Guinea, Australia, Palau, Honduras and more. But not one damn whale shark. On Grand Cayman, a South African guide told me there were so many off Mozambique that she got tired of looking at them. In Cozumel last April, I heard about a kid who, on his first openwater dive after certification, saw a 15-footer next to his boat. No doubt, I had the whale shark jinx. Then I received an email from the dive travel agency Island Dreams, with the heading "Whale Shark Season in Mexico," and a picture of a hotel big enough to house an army. I thought, "Oy. Huge hotels, all-inclusive partying, parasailing, screaming kids and . . . whale sharks?" Is this something real divers do? But I wanted to see the sharks.

Each summer, hundreds of whale sharks appear off the Yucatan barrier island of Holbox to feast in an ocean turned pea-green by a massive plankton bloom. The Holbox sharks are spread over dozens or even hundreds of square miles, in often murky waters. You can make the tiny town of Holbox home base, but if you're staying in the Cancun area, a van will pick you up at your hotel at 4 a.m. ( Undercurrent was the first publication to break the story of the Holbox whale sharks; read our review online at www.undercurrent.org/UCnow/dive_magazine/2004/HolboxIsland200410.html )

A potentially denser gathering occurs with some regularity in the open ocean off Isla de Mujeres. Some scientists believe the sharks arrive to feed off the spawn of tunny, a small tuna species. My late-July visit would be at the tail end of the full moon, when the tunny had spawned, and a huge aggregation was predicted.

But I couldn't deal with the mega-hotel or the Playa del Carmen tourist chaos, so I selected the 65-room Maroma Resort and Spa, a quiet luxury resort 30 minutes south of Cancun and 20 minutes north of Playa del Carmen. After turning off the main highway, I drove a meandering route through a forest of palmetto and poinciana, then past a faux-Mayan gatehouse to the lobby entrance, where the blue Caribbean was visible past the first of three pools. The concierge greeted me and my partner with margaritas, and we walked down a stone jungle path to our king-sized room on the second floor, overlooking another pool reserved for our cluster of eight rooms. But the pool was ours alone because no other guests were assigned to our cluster that week. At this point, I usually relax and let my partner wheedle her way into an upgrade or beachfront room. Not this time. No beachfront rooms available, and others would cost another $1,000 -- per day.

Staying put, I called Yucatek Divers in downtown Playa del Carmen, and spoke with owner Jean-Yves Moret, a Swiss national, to make arrangements for the next morning. The wind had kicked up, so Jean-Yves recommended cenote diving, but he noted that the weather would improve and would not affect the whale shark trip. So I scheduled three days of cenote diving and two days of ocean dives. Then we took our margaritas to the beach, reclined on a king-size beach bed under two umbrellas, and contemplated the blueness of the water. That night, we ate ceviche at the hotel bar. One restaurant offered high-end Mexican cuisine and western dishes, while the other, a French restaurant with only seven tables, offered exquisite, fresh seafood dishes. Later in the week, we tried El Fogon, a taqueria a few blocks away. It's open on two sides so it gets the breeze, and it has live music, lots of locals and tasty, inexpensive grub.

The next morning, a family of white-faced coatis descended from the trees to watch the bellhop load us and our gear into his golf cart for the drive to the parking lot. We hopped into our rental car and headed into the traffic on the main highway, passing police checkpoints on the way. Armed with submachine guns, the cops peered into our vehicle. We -- and all tourists -- passed without incident, but locals seemed to be stopped for sobriety, overloading and vehicle maintenance issues.

Yucatek Divers is two blocks from the ocean, in a two-story building across the street from a local breakfast joint that never seemed to be open.(We had a spectacular breakfast at the hotel.) After Jean-Yves checked C-cards, I signed the usual release forms (if I were to check an ailment, he said, I would be required to see a local physician), and we loaded the gear, aluminum 80s, weights, four divers and a guide into a van for the 30-minute drive to Chac Mool to dive the Kukulkan and Little Brother cenotes.

Geologically, the Yucatan is a limestone platform with many underground freshwater rivers running through it. At various places, the roof of a cave has collapsed, creating a sinkhole and exposing the cave to the surface. While a haven for hardcore cave divers, a handful of cenotes have caverns with natural light, and many have multiple openings, so it is possible to swim away from the entry point and see light in front of you. So, as our guide, Leopoldo ("Polo") Lacona, explained during the drive, there are special rules: a maximum of four divers per guide; no dangling equipment or knives; stay one meter away from the guideline and one meter from the diver in front of you; maintain buoyancy away from the bottom and the ceiling; carry at least one light and keep it on at all times; stay above 70 feet of depth; stay horizontal; no scissor kicking, only gentle finning from knee to ankle; any diver can abort the dive at any time; and obey the rule of thirds -- one third of a tank for the way into the cavern, onethird of a tank for the way out, and one-third as a reserve. Because most dives are a maximum of 50 feet deep, it's possible to stay in the water for 45 minutes or more.

At the site, I set up my gear on a table in the parking lot. Suited up in a 5mm wetsuit with less weight than usual, due to the freshwater, I walked down steps cut into the limestone to a pond under a stone overhang. After inflating my BC, I took a giant stride into the 75-degree freshwater and donned my fins. We dropped down to six feet, formed a line and swam past boulders from the collapsed ceiling. Rains had raised the halocline above its usual 30-foot depth, and for a while I was unable to see much, due to the shimmery emulsion. When I finally emerged into unbelievably clear water, I had the startling experience of seeing a diver floating in what seemed to be air.

After a 45-minute surface interval, we were back in at the "Little Brother" entrance at Chac Mool, and looking up at blue sky and vivid jungle greens through openings to the surface. Stalactites like gray sea pillars poked up from the talc-like bottom. It seemed like we were briefly beyond visible light as we passed through a large room at our maximum depth of 40 feet, then curved around back to the entrance. After we exited, Polo served sandwiches of "carne misterioso" and bottled water. It was just enough food to ruin my lunch without being enough food for lunch. No chips, fruit, dessert or juices, so next time I skipped it and had a great burger at Zenzi's on the beach in Playa del Carmen.

Next day, the wind was still up, so we stuck with cenotes. Rather than boulders and tree trunks, Dos Ojos offered long swims around sharp stalactites and stalagmites, limestone waterfalls and curtains resembling tunnels in the Alien films, delicate columns and deep, dark chambers leading to more than 60 kilometers of caves that then link to other sinkholes. On our second dive, we surfaced briefly in the Bat Cave, a large air dome populated by vampire bats, with sunlight beaming like a laser through a small opening to the surface, where a rope led to a platform in the water. I liked diving the cenotes -- I had never done it before -- and sites like Dos Ojos with its dark, forbidden tunnels gave me a taste of what cave diving could be like. But in the end, I'm a fish freak and longed for the open ocean.

The following day, we met at the dive shop for two ocean dives. Six Belgians formed one group, while my partner and I made a second group with a young Swiss woman with 10 dives. The gear was wheeled from the shop down to the beach, while we divers, in our wetsuits tied off at the waist, walked to the beach. Oops, not enough tanks. So the crew ran back to the shop to collect more, while we hung around in our wetsuits for too long in the morning heat. I waded to the 30-foot covered panga, clambered aboard the stern between the two outboards, and set up my gear before we finally took off for the 15-minute ride to Tortugas. With 10 divers, two guides, and a captain, the boat was crowded, and I wondered why they couldn't put out two boats if the rides were only 15 minutes. After a short briefing, I backrolled into 82-degree water and dropped to 70 feet over a flat sandy reef. The current was running at about one knot, and I drifted past enormous barrel sponges tilted away from the flow. Eventually I spotted a few of the hawksbill turtles that the place is named for, but there weren't a lot of fish, surely nothing sizeable. Polo inflated his surface signal at 800 psi, and we were soon back on board. The Belgians stayed down another 10 minutes, but in my mind the site didn't justify more time.

Polo handed out bottled water (no snacks), and we went ashore near a Mayan archeological site to do the necessaries in the bushes. A second dive at Sabalos proved more interesting -- hundreds of blue-striped grunts huddling out of the current under low coral ledges, a school of horse-eye jacks, southern rays, lobsters and a lionfish. Now here, I could have stayed longer. My partner had 1200 psi in her tank after a 49-minute dive, but Polo enforced the 800 psi limit, which the newbie we were paired with reached well before we did. The Belgian group again surfaced after we were back on board. For comparison, although the isle of Cozumel can be viewed from the mainland, the underwater topography there is much more dramatic and the sea life larger and more diverse.

On Wednesday, a van picked us up at our hotel and we headed to Cancun to begin our whale shark expedition. During the ride, the guide handed out brochures advising what to do -- and mostly not do -- around the sharks. We were asked not to use sunscreen, because the nonbiodegradable stuff comes off in the water and apparently is ingested by the sharks, to their detriment. Regardless, most of the 12 adventurers greased up, then piled aboard a 35-foot modified panga to set off past Isla de Mujeres for the 90-minute ride to the feeding frenzy.

But it wasn't the sharks that were in a frenzy, it was the tour operators. At least 60 boats clustered in a half-square-mile of blue water, maneuvering slowly around several hundred sharks. Snorkelers milled around the surface, three or four to a shark, often ignoring the two-meter distance limit. Some waited for a shark to come to them. Others thrashed off in pursuit.

Our boat had a different, and I hope, kinder plan. The captain hung around the edge of the feed, away from a lot of the chaos. We had been set up in groups of four and cautioned to stay with our guide, Luis. We'd be in the water for 10 to 15 minutes, then climb out so the next group could go in. "When I say 'jump,' you jump," Luis said. "Don't wait. When I say 'out,' get out, don't worry. You'll get to jump many times." So after 791 dives that lacked swimming with one Rhincodon typus, I jumped.

I'd like to believe the sharks were unaffected. They never seemed to change course. They just swam slowly through the food, oval mouths agape, tiny eyes watching the curious human-fish trying to keep up as they swam sinuous S shapes in the blue. The largest were probably 20 feet long, cruising close to the tiny humans, daring us to grab a fin. Nobody did. Feeding mantas clustered in twos and threes, and held our attention until the next shark came into view. Then we were off again, full speed ahead. My best encounters were away from guide and group. I'd pick a shark, wait, and then have it to myself, 30 seconds with the biggest fish in the sea. An awesome and ancient power, unconcerned with money, man, politics or the spectacle surrounding itself. Marvelous, stunning, inspiring, humbling. I loved the sharks. I hated the human spectacle.

On the way back, we anchored in the shallow lee of Isla de Mujeres with many of the other shark boats. Cervezas and sandwiches were handed out, and fresh ceviche prepared. I chilled in the calm water and considered the events of the day, weighing the wonder of the whale sharks against the impact on them, wondering if I was part of a larger problem.

-- D.L.

Divers Compass: Cancun is easy to reach nonstop from many cities, with low prices ($650 from Newark, as little as $514 from LAX); to get my dive bags' weight below 50 pounds, I checked three bags and paid $40 extra because each bag over 50 pounds would have cost me $200 . . . I reserved a car from Thrifty for only $42 for the week, and then found that if I didn't take the $140 Limited Damage Waiver insurance, they wouldn't rent to me . . . Yucatek Divers would have picked us up and returned us to the airport for $70 each way, and they would also have taken us from the hotel to the dive shop for a fee, but when I added it all up, a car was cheaper and gave us the freedom to check out other attractions and restaurants . . . I went to the Mega store in town and bought a case of water, snacks, and sun lotion; they have everything you need, including beer and well-priced tequilas . . . The Maroma Beach Resort set me back $3,300 for the week for a pool-view room with king bed and a brilliant table-service breakfast included . . . If you don't mind a huge hotel, Island Dreams ( www.divetrip.com ) offers packages at the beachfront Playacar Palace, just one block from Avenida Cinco and its rope-a-dope carnival atmosphere . . . Bring your own gear and Yucatek Divers charges $75 for a two-tank ocean dive and $120 for a two-tank cenote dive, or you can book three two-tank ocean dives, one two-tank cenote dive and two tanks in Cozumel for $380; the whale shark snorkel trip cost $220, including the round-trip van ride from my hotel . . . In the afternoons, I drove to attractions like the ruins at Tulum, where ticket lines were long, and the weather is hot (join a group, if you can); the ruins at Chichen Itza are spectacular and well worth the trip, but it takes an entire day . . . Websites: Yucatek Divers - www.yucatek-divers.com ; Maroma Resort and Spa - www.Maromahotel.com