Considering that Titanicwas the hottest movie last spring, it’s a source of nervous amusement that icebergs—albeit small ones—are banging along the hull of our little ship and the crew is unconcerned. All the passengers are out on deck watching our passage up the fjord toward Chenaga Glacier. Harbor seals and their pups, hauled out on the ice floes, raise their heads lazily to regard us. At the head of the fjord, the captain nudges our ship toward the broad white wall of the glacier front, and we watch it discharge chunks as big as cathedrals. On a cliff nearby we count nine mountain goats clattering along the ledges. A pair of loons flies across the stern.

It’s almost 10 p.m. and, on this midsummer night, it is still sunny and bright in Prince William Sound. During dinner we squeezed through Dangerous Passage and paused in Icy Bay to watch humpback whales cavorting just off the starboard bow, a calf particularly exuberant in its rolling and breaching.

By 11 p.m., evening has settled onto the sound. The water has turned to silver, and snow-fields on near mountains have grown dusky—but in the high distance the ice fields are still gleaming in sunlight.

One by one, passengers fold into their cabins and draw their curtains against the perpetual gray of the Alaskan summer night.

This long day began in an Anchorage hotel lobby. Passengers boarded a bus that took us south along Turnagain Arm, stopping for us to look for belugas and to watch a flock of Dall sheep on the cliffs. We drove up Portage Valley to peer at the glacier and tour the handsome new visitor center and museum. Then we climbed off the bus and onto a train, which rattled through a mountain tunnel to the ramshackle port of Whittier, tucked into a western arm of the sound. There we boarded the Spirit of Glacier Bay,a compact 52-passenger ship operated by Alaska Sightseeing/Cruise West, and set sail.

Prince William Sound is notorious for miserable weather, but as it happens, the northern gods have blessed us with five days of dazzling sunshine. The air is so clear it seems like a fine lens, etching out the smallest details at great distances—the eyes of eagles, the whiskers of sea otters. Often the sea is a slick of satin, reflecting the dark green forest, the playful waterfalls, the dazzling ice.

We spend our days—and nights—mostly on deck, spellbound by our passage through a landscape symptomatic of enormous, swift forces—the grinding of glaciers, the sudden adjustments of earthquakes, annual freeze and thaw. And, in recent years, the carelessness of man. It was in Prince William Sound, in 1989, that the Exxon Valdezcrunched into Bligh Reef and spilled more than 11 million gallons of crude oil, devastating fisheries and marine life. And although we see no evidence of the oil, naturalists say a lot of it is still there, sunken below the surface. Ten years later, wildlife seems plentiful, despite the general and mysterious decline of fur-bearing marine mammals throughout the North Pacific.

On all sides there are the amazing tidewater glaciers, like massive tongues licking down from the vast upland ice fields, and each is different in size, in angle of drop, in mood, in how much debris it carries.

One morning, we awaken at the face of Harvard Glacier, at the head of College Arm, discovered by the scholarly Harriman Expedition of 1899. Harvard is active this morning, with roars and cracks and tons of ice peeling off and crashing into the sea. We watch for a while, then the captain turns the ship to ride a calving wave and we sail down past Bryn Mawr, Vassar, Wellesley, Barnard, and Holyoke glaciers. (It amused the scientists with Harriman to name the glaciers on the east side of the fjord after men’s colleges, those on the west after women’s schools.)

We follow Barry Arm up to its head, where three glaciers converge from the heights: Barry, Coxe, and Cascade (near a waterfall wild with shots and wheels). The captain executes a skillful bow landing and we scramble down to poke along the cobbled beach. Beyond, a yellow haze of pollen hangs in the spruce forest.

For a couple of days, we can see the large icebergs drifting across the sound from Columbia Glacier, the largest in the neighborhood. They have melted into fantastic blue ice sculptures worthy of the Ritz buffet—swans and elephants and ballerinas. When we finally sail up Columbia Bay, the pack ice is solid almost six miles from the glacier. We lean over the rails, listening to the fizz and pop of melting ice compressed for centuries.

Besides Whittier, we call at two ports: Valdez and Cordova. Valdez is the sprawling terminal for the Alaska Pipeline, where North Slope oil is pumped into tankers. Several of us go on a kayaking tour past the tanker docks toward the site of Old Valdez, destroyed in the 1964 earthquake.

I adore Cordova, which seems the perfect northern town: a harbor full of salmon boats, bookstores, community pool, ski area, and no roads to the outside world. Cordova’s neighbor is the Copper River Delta, a huge wetland where braided rivers run. We take a tour bus for 50 miles across the delta, pausing to watch beaver and trumpeter swans and moose.

Other than these towns, human presence in Prince William Sound is sparse—fishing boats, a few Native Alaskan settlements, day-tour boats out of Whittier, occasional kayakers.

As cruise ships go, the Spirit of Glacier Bayis homey, intimate, informal. There is a tiny bar in the lounge, which has large windows, lots of binoculars, and an impressive library of natural history books to enlighten passengers about this part of Alaska. There’s also a VCR and selection of videos. We gather in the dining room for the tasty, hearty meals. Then we grab our warm jackets and rush back up to the windy deck. We don’t want to miss anything. We are here to see the Great Land.