We were afloat in the Arctic, and along the horizon, as far as the eye could see, shimmering cliffs of ice towered as if the Ancient Mariner's tale where "the ice was all between" had come true.

It was a surrealist's fantasy. The Beaufort Sea was calm, the sky was blue and the sunlight carried a crisp, clear edge of chill. Our little blue-and-white ship World Discoverer seemed trapped between the icy cliffs on one side and the glittering sand-colored skyscrapers of an Arctic Manhattan twinkling with lights and belching flames on the other. Fire and ice in a vast, flat sea.

We were five days out of Nome, Alaska, attempting the first passenger-ship crossing of the Northwest Passage from west to east, and we were looking at something no map and no amount of reading had prepared us for -- one of the Arctic's more devious tricks, a mirage effect called "looming." The stark icy cliffs to our port side were illusions, the flat icecap of the Beaufort Sea reflecting against itself in the morning sunlight. (How many explorers desperately searching for the Northwest Passage during the last 400 years had seen a similar wall of ice ahead and turned back?)

To the starboard side, an indefinable distance away in the clear air and flat Arctic landscape, the "city" was Prudhoe Bay, its oil platforms and administration buildings reflecting upside-down and rightside-up in several layers, as if suspended in a gray aspic between sea and sky.

But illusions aside, the reality was that the ice pack below was much heavier than expected. Since dawn, when we had witnessed another rare phenomonen, a "green flash" at sunrise on the sea, we had watched the ship weave its way through the thickening ice until it reached what the officers called a percentage of nine-tenths -- meaning that 90 percent of the surface was covered by dense ice. At 9 a.m., Capt. Heinz Aye and ice master Capt. William Stuart (an expert brought aboard specifically to guide the vessel through the ice pack) made the decision to reverse our course. At least for the moment, we were turning back.

Sailing through the Northwest Passage may well be one of the last great adventures on earth for the well-heeled passenger who's been everywhere. The landscape of the frozen Arctic is still as barren and hostile as it was nearly 100 years ago when it reduced doughty explorers and expeditioners to starvation, murder and cannibalism, and wiped whole ships off the face of the earth.

For anyone whose idea of a cruise is a warm, lazy sail through the islands of the Caribbean or the South Pacific, a 32-day voyage from Nome to Halifax across the Arctic archipelago would have about as much appeal as a hiking tour through purgatory or a weekend in a walk-in freezer.

But one look at this motley crew of adventurers, some 80 of them with a median age of 69, standing on deck bundled up in their Society Expeditions parkas, dispelled any doubts. Scanning the horizon with binoculars, photographing ice floes, they were giddy with excitement. For the moment, at least, it seemed to be worth the $14,900 to $26,300 apiece they had paid to attempt the Northwest Passage, with no guarantee of getting through and no definite itinerary along the way.

A surprising number of men and women had come alone, leaving reluctant spouses behind in warmer places. For many, there was the tug of the unknown, the "because-it's-there" spirit.

"From the time I was 12 years old, I read everything about the polar expeditions I could get my hands on," an Arizona woman said. A Los Angeles man was celebrating his 50th birthday by sailing as close as possible to both poles; he had completed an Antarctic cruise earlier in the year. Even a young stowaway who said he was "desperate" to be among the first to transit the Northwest Passage west to east had wangled his way on board in Nome by getting identification badges from a disembarking passenger. (Discovered a few hours later, he was put off at the first port of call, remote Little Diomede Island in the Bering Strait. The Eskimo chief of the tiny village said the young man could stay until the biweekly helicopter from the mainland arrived, "but he has to work.")

After more than five hours of negotiating the ice-laden Beaufort Sea in a zigzag route that took us through waters so shallow there were sometimes only three of four feet of clearance underneath us, we began to appreciate the World Discoverer's ice-hardened hull and shallow draft. From time to time across the frozen way we could catch glimpses of the U.S. Coast Guard icebreaker Polar Sea, which made headlines early last summer by proceeding across the waters of the Canadian Arctic without asking permission from Ottawa. (We, on the other hand, not only had permission but received the generous cooperation of the Canadian Coast Guard at several sticky spots along the route.)

Most of us quickly became obsessed with observation and record-keeping -- scribbling in journals, making photographs and sketches, even videotaping with murmured commentary into the side of the camera. We haunted the ship's library for books about the Arctic and scoured the posted navigational charts. We flocked to 25-year-old documentary films with titles such as "Group Hunting on the Spring Ice, Part III" -- and a sound track entirely in the Netsilik Eskimo dialect -- and attended rambling discourses on everything from lichens to permafrost.

The mystique of the Northwest Passage may come in part from the legendary explorers that were here before us: Martin Frobisher in the 16th century, who received a cheery goodbye wave from Queen Elizabeth I and came back with both an Eskimo and a glittering mineral (which later turned out to be iron pyrite, or "fool's gold"), but failed to find a way across to China; Vitus Bering, a Danish captain in the 18th-century Russian navy, who spotted Alaska but died of scurvy on the voyage home; Sir John Franklin, stubborn, duty-bound and accident prone, lost at the age of 59 on his third search for the passage in the 1840s, his body never recovered, his two ships most likely crushed to bits in the grinding ice; the Americans Aldolphus Washington Greely and Charles Francis Hall and all the others who set out to find the Franklin Expedition, only to get lost themselves; and finally the Norwegian Roald Amundsen, who spent three years in his combined effort to study the North Magnetic Pole and find the Northwest Passage. When his successful journey was ended in 1906, his triumph was undiminished by the fact that the Panama Canal, with its own shortcut to the Orient, was well under way.

But the ultimate irony, as shipboard lecturer Graham Rowley, noted Canadian Arctic archeologist and expeditioner, pointed out, was that even while the explorers were starving to death, entire families and groups of Inuit were living out normal lives only a few miles away. The Europeans who failed to adopt Eskimo ways or utilize Eskimo guides always underwent undue suffering and deprivation.

More than once aboard the World Discoverer we were to feel pangs of guilt hearing about explorers who had to boil and eat their own boots, while our growing problem was weight gain from the lavish, beautifully prepared meals from our Viennese chef Hans Baumhauer.

On many nights, during the short period of darkness, those of us who asked for a wake-up call were awakened to see the aurora borealis; we stood shivering on the forecastle away from the deck lights while the liquidy sulphur green patterns streaked and swirled in the sky.

Our weather varied tremendously, from a balmy, sunny, 68-degree morning at Herschel Island, an abandoned whaling station at the northernmost tip of Canada's Yukon, to fresh snow, a 32-degree chill and driving sleet blown by an icy wind like little nails being hammered into the skin at Cambridge Bay on the east end of Victoria Island.

The day after we left Cambridge Bay, as we sailed the gulfs and straits between the mainland of the North American continent and the islands of the Canadian Arctic, we encountered gale-force winds of 45 knots, and the captain ordered the cabin portholes covered on all the lower decks. Through the night, we picked our way through the ice of Queen Maud Gulf, and by midday, in Requisite Channel, we were pitching and rolling in a very rough sea and forbidden access to the deck. That was one of the rare days we did not attempt a rubber boat landing on shore.

The Canadian Coast Guard icebreaker Camsell informed us that the storm we were experiencing had destroyed many of the buoys in narrow, shallow Simpson Strait, which lies between the mainland and King William Island, and offered to lead us through. Afterward, we anchored near each other, and the officers and crew of the Camsell came on board the World Discoverer for a lively evening in the main salon bar.

The next morning, we called at the hamlet of Gjoa Haven on King William Island. ("Joe Haven," as the locals pronounce it, was named for Amundsen's ship, the Gjoa, which spent two winters here. Relics, graves and skeletons of the ill-fated Franklin Expedition also have been found on the island.)

Gjoa Haven, although tidier than some, was typical of most of the Inuit villages we visited. Everyone had a fairly new wooden house, painted in bright colors, which had been delivered in pre-fab state on the annual supply barge from Fort Smith; half a dozen broken snowmobiles; barking dogs tied up; polar bear, seal or musk ox skins drying on clotheslines; fishing boats on the beach with outboard motors; a couple of three-wheelers for the wife and kids to tool around town on; a color TV set; maybe even a double-cab red pickup, despite the pronounced shortage of roads.

Since the World Discoverer's sister ship, the Society Explorer, called here last year (when it was known as the Lindblad Explorer) on the first east-to-west transit of the Northwest Passage by a passenger ship, Gjoa Haven has become more interested in tourism, offering, among other packages, a traditional spring Inuit experience: a two-day dog-sled trip across the ice from Gjoa Haven to Spence Bay on Boothia Peninsula.

Our cultural exchanges with the Netsilik Inuit of Gjoa Haven left both sides more than a little bemused. We swept through the Hudson's Bay Store, the tiny hotel and the Kekertak Co-op, buying soapstone carvings, traditional knit caps and applique'd wall hangings at a ferocious rate. We visited the nurse's station, post office, school and new city hall, filled with curiosity (and a desire to get in out of the cold). We marveled that a box of sugar-coated cereal cost more than $5, the same price as an artfully carved caribou pendant. The natives, on the other hand, were politely unsurprised at our loud swoopings and our rudeness in asking direct questions about their lives, a social gaffe among the Eskimo.

The elders of the village arranged a drum dance for us, and the caribou-clad men and women climbed on board our red rubber Zodiacs a few at a time to be ferried to the ship. Almost none of them spoke any English, and they wandered around the World Discoverer staring enchantedly at the hammered-brass palm trees in the main salon and the live green plants and trees throughout the ship, while cruise director Werner Zehnder and his staff searched for an interpreter and tried to determine who was supposed to bring the drum. But the show eventually went on, in the traditional relaxed fashion of Eskimo time, and as a final fillip, several of the Inuit women experienced their very first elevator ride.

From Gjoa Haven we turned north, bound eventually for the northernmost point on our voyage, Little Cornwallis Island, at 75 degrees 23 minutes north. En route, we made our own soundings with a portable echo sounder from one of the Zodiacs that ran ahead of us up the James Ross Strait; spotted a polar bear with two cubs just inside the mouth of the narrow Bellot Strait, the often mist-shrouded key to the Prince Regent Inlet; played tag with a rare bowhead whale that teased us with arches and arcs, tumbles and rolls and spouts, its elephant-gray skin gleaming in the water.

At Beechey Island, where the Franklin Expedition spent its first winter, we saw the graves of three sailors who died and were buried there. (One, John Torrington, was disinterred, examined and photographed in 1984 in a remarkable state of preservation.) As we walked across the island from the gravesites to the cache and "post office" used by early explorers, we felt like moonwalkers crossing a lifeless planet where there was nothing except rocks and lichens and rusted 19th-century tin cans discarded by expeditioners.

After Beechey Island, we encountered the first huge icebergs from Greenland's glaciers, and after several calls at villages on Baffin Island, we crossed into Baffin Bay and the waters of the Atlantic Ocean. On Tuesday evening, Sept. 9, 1985, precisely at 8 p.m., we officially completed the first passenger-ship west-to-east crossing of the Northwest Passage, the 36th ship of any kind in history to make the passage.

While there would be two more weeks of our cruise, and visits to unexplored fiords on Baffin Island's east coast, Greenland's west coast, Labrador, Newfoundland and Nova Scotia, we had already accomplished what we set out to do -- to travel a mysterious and notorious sea route in spots where no passenger ship had ever been before, and, in the doing, perhaps learn more about ourselves.