More filming today. At nine in the morning we are on a MarViva boat, speeding out of the bay and around to the other side of the island. This boat is smaller and more mobile than the Ranger, larger and more stable than our little dingies, and MarViva has offered to transport the diving team from one site to another.

Miguel (a MarViva captain) steers, Mar watches the water. Every once in a while fins appear momentarily, or something jumps and lands with a splash. For a few minutes we have dolphins at the bow. The marine life at Cocos, even on the surface, is extraordinary -- but in this place it is the norm. The island itself is verdant and wet, quite literally dripping with water; it falls in threads down the island's steep green sides. Some of the waterfalls disappear into the forest. Others have carved long channels from the top of the island down to the sea. Cocos gets 280 inches of rain a year. There is so much water here that the park rangers who work on the island (they rotate month-long shifts) have constructed a hydroelectric dam to power their base.

Cocos Island: A series of islands, really, one massive and countless miniature peaks that rise from the middle of the Pacific Ocean. The main island is cloaked in forest. The smaller islets, of which there are many, all around the island, are little pyramids of jagged rock. Most have at least one hollowed-out cavern at the water line; when the sun hits them right they look like thatched huts with doors.

The islands are the center of a protected area that includes 24 square kilometers of land and 972 of water. The difficulty of access to the island kept it immune from human influence until the end of the twentieth century, when fishing boats, driven farther from shore by depleted fisheries, began to encroach. Cocos, however, has been lucky. The incredible number and diversity of species in and around the island have brought it international renown, and -- declared a UNESCO world heritage site in 1997, patrolled by MarViva and government park rangers since 2002 -- it has retained its character of wilderness.

We're here! We are at Cocos. We first saw the island, a gray splotch on the horizon, yesterday morning, and by the afternoon we could see its rocky crags, the lush green hills, and two MarViva boats anchored in the bay. Everyone was excited. We had Juan Pablo (director of VOEA and one of Ranger's divemasters) high up on the masts to film, swinging in the rigging like a spider monkey. Our two temporary guests (Marcela, director of communications for MarViva, and Alex, from FAICO) work every day to protect the island but had never seen it, so for everyone on board -- divers, biologists, Costa Ricans, Europeans, and Americans -- this was the opportunity of a lifetime.

At the twelve-mile border of the marine park we passed a long-line boat, just sitting there. There was a crew of five or six, a tangle of green and black flags rising from the boat (they are used to mark the long-line buoys), and "Punta Arenas" -- the boat's home port -- painted on the stern. Marcela says that the boats always wait on the border for a moment to enter, or use their knowledge of currents to let their lines drift into park territory even while the boat is legally outside.

It's obvious enough why they would. No sooner had we entered park waters than two dolphins joined us at the bow. Marcela said, "This is how you know you're getting to Cocos."

We left Golfito last night around 7 and have been traveling southwest toward Cocos ever since. The ocean has been perfectly calm. Those among the new crew who have never spent more than an afternoon sailing (myself included) are learning what it means to live on a boat from the seasoned sailing veterans of the Ranger crew.

The Ranger is here! She arrived yesterday. Everything has been crazy since -- people running around buying supplies, fixing engines, finding old friends -- and we're leaving for Cocos tonight. I'm more excited than I can write.

We (Xavier, myself, and some of the MarViva crew) went out to meet the Ranger yesterday morning in one of MarViva's boats. We were up at 5:30 and on the water by 6:00, coasting towards the Golfo Dulce through a morning fog. For fifteen minutes or so we had two dolphin escorts riding under our bow.

We met the Ranger near the mouth of the gulf. What a beautiful boat! She appeared on the horizon; we passed the binoculars back and forth until there was no doubt -- her white pontoons were bright against the water, and the Oceana logo was clear against the white. The crew were all on deck, grinning and waving, taking pictures of us taking pictures of them. When we pulled the MarViva launch alongside the larger boat there was a happy chaos of hugs and introductions.

Xavier has been in touch with the Ranger crew; they are nearby and should arrive in Golfito tonight.

We have been working closely with the staff of MarViva to prepare for the trip to Cocos Island. Some background on MarViva: The organization was created in 2002 to enforce protection in the Eastern Tropical Pacific Marine Conservation Corridor (a string of five islands that includes Cocos, off Costa Rica; Coiba, off Panama; Malpelo and Gorgona islands, of Columbia; and the famous Galapagos of Ecuador) and throughout the Meso-American reef system, which runs from the Caribbean coast of Mexico to Honduras. Both areas are extraordinary. The islands that make up the Marine Conservation Corridor, on the Pacific side, all belong to the same geologic formation -- a ring of heightened seafloor that looks like a mountain ring on a topographical map. Because of the magnetic peculiarities of the area and the many currents that converge here, the corridor is a destination -- and now a haven -- for migratory species like sharks (silky, scalloped hammerhead, Galapagos and whitetip, among others), billfish (swordfish, marlin, sailfish), tuna, endangered sea turtles (leatherback, east Pacific green, olive ridley, loggerhead) and endangered great whales (blue and humpback). The coral reefs by some of the corridor's islands are among the few in the Eastern Tropical Pacific.

So here we are, waiting for the Ranger in Golfito. And waiting keeps us busy. There are arrangements with the marina to be made, communications technology for the boat to be tested, press releases to be sent out. Xavier is on the phone non-stop; I'm trying to learn as much as I can about Golfito, Cocos Island and the water in between before we abandon land and internet connection both.

Golfito ("little gulf") is a very small town on the Pacific coast of Costa Rica, just north of the Panamanian border, set on a "sub-gulf" that emerges from the larger Golfo Dulce ("sweet gulf") like a droplet of water from a larger drop. It was born as a banana town: from 1938-1985 Golfito was the southern Costa Rica headquarters of the United Fruit Company -- the much-vilified banana empire notorious for its involvement in the 1954 U.S.-sponsored coup in Guatemala, for widespread repression of workers, and for having economically colonized much of Central America.

Golfito boomed with the banana trade. Trains carried supplies in and bananas out. The town grew along the track and is still one long, narrow strand, nearly all the buildings set along one road. In the old days a train ran here, slowly; people traveled from one end of town to the other by grabbing hold as it passed. The Company -- and people here still refer to it as "la Compañia" -- built a hospital, schools, a pier, and populated "el pueblo civil" with worker houses.

I'm in Golfito. On one side there is jungle; on the other, ocean, and the Ranger should arrive any day. The adventure begins.

The trip to the ocean has been mostly through the air. I took a plane from DC to Miami; from Miami to San Jose; and this morning, in a plane that would fit in my bedroom, from San Jose to here.

Costa Rica is mountainous. From above it looks like wrinkled silk, the peaks clay-colored, the valleys full of a deep green, the ridges veined with dirt roads. I descended into San Jose for a night, and this morning, with Xavier Pastor (director of Oceana Europe), took to the sky again. The plane was no more than an aluminum cocoon -- I think it held 10 of us, tightly -- and I felt as foolish as a deluded butterfly trying to fly cocoon-bound. We at least had wings and we rose, miraculously, up out of the peaks until we were looking down again on the wrinkled land.

It wasn't more than twenty minutes before the ocean appeared at the horizon. It stretched forward to meet us, a smooth panel of electric blue. There was a long band of beach between the forest and the bright, bright sea. I think I will move here.