Only days before we left for the Pacific Northwest, I was beset by some nagging questions. Could a fairly demanding couple and their 5-year-old daughter survive a week's trip to Alaska on a 976-passenger cruise ship? More to the point, would our Kate perish from boredom, faced with a sedentary shipboard existence and the company of hundreds of people on the far side of 60?

An eleventh-hour call to Royal Caribbean Cruise Line helped put me at ease. The reservations agent, a sympathetic sort, couldn't judge how many children would be aboard but assured me there would be enough. "I have a friend who just came back from there and said her two kids had a terrific time," she told me. Then she added: "I wouldn't pass it up. By the time our children are grown, there may not be any eagles and whales left to see."

We never did spot an eagle, though many of our shipmates did, but in a week on and off the Viking Serenade we saw whales and seals and ice-blue glaciers caving into fiords, native Americans carving giant totems, kids pulling in salmon hand over fist from icy streams. We also saw more rain than we wanted to see, more food than we could hope to eat and enough variety-show entertainment to thrill the ghost of Ed Sullivan.

As for Kate, she was surrounded by so many young bloods (80, including teenagers) and hit with such a full curriculum by the Kids, 'Tweens and Teens program that we lost track of her for hours on end.

On that Sunday afternoon in early August when we boarded the Viking Serenade, Vancouver, B.C., was in a rare 90-degree funk. To a New Jerseyite it was just a warm, dry summer day, but here people were moving about in a Singaporean slouch. It didn't last. When I woke the next morning there were dense clouds outside our porthole and a slip of paper under the door with the daily weather forecast, one we would see all too often: rain and temperatures in the mid-fifties. But who could complain? Part of our motive was to beat the summer heat. Anything above 80 degrees is news in the piney stretch of southeast Alaska along the Inside Passage, which runs for 950 miles from Seattle to well north of Juneau.

No, you don't go to Alaska for a tan. There was a swimming pool on deck, but it had a retractable plastic roof that was closed as often as not. You can hit days of almost tropical sensuousness (we had one), but raincoats come in handy. What you can count on, in the protected waters of the Inside Passage, is a smooth, dramamine-free ride. There is almost none of the pitch and roll, or the green faces, of the open sea. At times you have to look out the window at the passing shoreline to see if the ship is moving.

One other question nagged at me: How would we ever get through two full days on ship before visiting our first port of call, Skagway, on Wednesday morning? The answer: quickly. At 10 a.m. Monday, I joined my wife, Pam, and 50 others (mostly women) around a somewhat crowded nightclub dance floor for my first aerobics class ever. I pranced and kicked to the music, and finally caved in trying the killer abdominal stretches.

At 11 a.m. a little girl walking on the drizzly deck shouted, "Whale!" Her cry didn't exactly evoke Ahab, but out came dozens of cameras and binoculars as a giant couple spouted and fluked their way south. In no time it was 4:45 p.m. and we were having tea (and ice cream sundaes, cookies and cakes) at the Sunshine Bar as raindrops plopped on the pool roof.

Sitting side by side next to a broad window, looking happy and secure, was a couple from Vancouver -- she a Canadian, he a Brit -- watching the piney shores glide by and charting our progress with a six-foot-long pullout map and guide to the Inside Passage, bought in the ship bookstore. I asked if they had spotted any wildlife. "I think the terrain's too steep for that," said the man, sounding as though he knew.

This was the second couple I had met poring over the guide; the other was Australian. I could see a pattern and it didn't surprise me: The passengers who seemed the most curious, the most studious about geography and wildlife were British Empire types. As for the Americans, a distinct majority, they ate and played and danced and gambled and lugged about their cameras for photo opportunities -- sightings of glaciers and whales, seals and salmon-hunting bears.

Tuesday, though damp and cool, was perhaps the most riveting day of the cruise. At 11:45 a.m. I quit the gut-busting aerobics class in the middle of the abdominal assault and caught the finish of a lecture by John Brand, a university professor of geology and house expert on glaciers. "I'm sorry about the weather," said Brand, "but precipitation is what makes glaciers."

At lunchtime, we headed into Tracy Arm -- a glacier-lined fiord and the scenic highlight of the week. All eyes in the dining room were directed at the windows. Broken-off chunks of icy-blue glaciers floated on the water. Eric, a mustachioed and comical head waiter from the Philippines, stood in the window holding up a large drawing he'd made of a whale, as if to say: This is the closest you'll get to the real thing, folks. Moments later I heard a whop and looked out to see some playful humpbacks break the placid green surface with a series of gushes and flukes (the flipping of the whales' tails). A number of diners rushed to the windows, yelping and whistling.

In the cruise business Alaska's Glacier Bay is often touted as the ultimate in glacier- and wildlife-sighting, but Royal Caribbean likes to think Tracy Arm is every bit as impressive. "We probably get up closer to the glaciers here than they do at Glacier Bay," said Viking Serenade Captain Thomas Wildung, square-jawed and blue-eyed, the image of the Swedish skipper.

That afternoon Wildung maneuvered the ship to within 100 yards of the shore. On the deck, a cocktail cart was rolled out for passengers standing in the drizzle, oohing and aahing, snapping and taping. The steep shoreline looked to me like a glassy blue cityscape. Each time a hunk of ice fell with a thunderous clap into the water -- a process called calving -- people whistled and cheered. Ice floes drifted away from the fractured shoreline, and on many of them seals hitched a ride.

Up on the bridge, Wildung was orchestrating a command performance. An orange lifeboat was sent over the side with a dozen crew members wearing survival suits. One by one they jumped into the frigid waters -- fatal in minutes to the unprotected human -- and flopped around like seals. Some scooped up chunks of floating ice to be brought back for an ice-sculpting demo.

For the next three days we were dropped on shore to comb a variety of southeast Alaskan ports -- Skagway and Haines on Wednesday, Juneau on Thursday, Ketchikan on Friday. With only a half-day to explore Skagway and the environs, we made like the prospectors of 1898 who came up by ship from Seattle and raced inland to the Klondike gold mines. We fanned out and walked the false-fronted main street with its well-preserved (by the National Park Service) gold-rush flavor, rode the narrow-gauge White Pass & Yukon Railroad, took van trips to the Gold Rush Cemetery, rented rods to fish for salmon in the quiet bay.

Haines, which we visited for a few hours that evening, was by most accounts a lost cause. If you didn't sign up for an $80 salmon bake at Totem Village, you were left to ride a schoolbus into town, where the choice was browsing in curio shops or slugging down a drink in a rough corner bar. Kate perhaps had it best, snoozing in our triple-bunk room under the eyes of a committee of teenage girls we'd hired as babysitters.

The next day, in a fine mist, we three enjoyed slogging about Juneau, an unlikely-looking state capital of 25,000 citizens. The town nuzzles up to steep green mountains streaked with waterfalls, the main shopping streets are overhung with eaves, and the capitol looks like a blocky stone office building -- though tours are conducted "whenever there's a crowd," a guide told me. I liked the dark, art deco-ish Westmark-Baranof Hotel, the bawdy-looking but well-kept Alaskan Hotel & Bar with its $45 rooms, and the Mount Juneau Trading Post on the main drag, full of trinkets and treasures fashioned by Tlingit and Haida craftsmen.

On Friday morning, when we pulled into Ketchikan, which crouches Juneau-like at the edge of a green wilderness, the sky was at last a deep blue.

In a crafts shop, a young clerk, learning I was from New Jersey, made a curious comment: "Oh, you're so lucky. My friends say it's beautiful. I want to go to Sayreville, where all the rock stars are from."

We wanted to see Ketchikan's famous totem displays. There's an indoor collection of more than 30 historic poles 85 to 150 years old at the Totem Heritage Center on the edge of town, and 14 tall and colorful specimens scattered through the wooded Totem Bight Park, north of town.

In a shed beside the park we watched Nathan Jackson, a Tlingit carver who has displayed his skills from London to Brisbane, Australia, chisel a thick log, with help from his 10-year-old son.

In our last minutes in Alaska, just before the Viking Serenade nosed south for Vancouver, we explored Ketchikan's Creek Street, a labyrinth of plank walkways and frame houses built over the water.

Once a red-light district, Creek Street is filling up with shops and restaurants, but the gentrification is not severe, and much of the old texture remains.

As we steamed south that afternoon, Alaska suddenly turned into Aruba. The pool roof was drawn back, passengers came out in swimsuits, and bartenders moved about the sunlit deck bearing exotic drinks.

Later, as we dressed for dinner, the ship felt as though it had stopped. The captain was up to his old tricks. We were in the narrow, bottle-green waters of Misty Fjord National Monument and Wildung was slowly wheeling the ship about hoping to sight some bears he'd passed the week before, hanging out at the shore hunting for salmon.

We saw no bears -- it was too hot, said the captain; salmon like to swim in cold water. Looking back, though, I think I treasure those enchanting moments before dinner as much as any -- a late sun slanting through the pines, most of the passengers closeted in their rooms preparing for the formal Captain's Night, a few of us talking in respectful whispers at the rail. Would that all cruises were filled with such moments.

David Butwin is a writer living in Leonia, N.J.

WAYS AND MEANS Royal Caribbean was new to the Inside Passage in 1990, and when it opens its 1991 season in Alaska it will dispatch a different ship, the Sun Viking. Accustomed to balmier climes, the 724-passenger Sun Viking is fitted with broad deck space for outdoor play. All the better for group aerobics and glacier-watching, as long as the weather holds up.

There will be weekly seven-night sailings out of Vancouver, B.C., from Sunday to Sunday, late May to mid-September. Rates range from $1,095 to $3,395 per person, depending on the size and location of the stateroom and the time of season. Dress is not overly formal -- slacks and sport shirts some nights, jacket and tie on others. A dinner jacket or dark suit is recommended on two evenings, but some gents get by nicely with sport jacket and tie. For reservations and information call a travel agent or phone 800-327-6700.

Among other cruise lines plying the Inside Passage, Holland America and Princess have loads of experience and solid reputations. Royal Viking is also an Alaskan bellwether; Cunard Line dispatches the sleek Sagafjord; and, among the smaller lines and ships, Clipper Cruise Lines sends the Yorktown, a 138-passenger vessel, up to the glaciers and totems for closer looks than the leviathans allow.

Though it's been assumed for years that cruising in Alaska is for older, generally retired people, this is not always the case, and in fact the cruise lines are luring a younger clientele to the Inside Passage these days. There are families with young children, plenty of teenagers, yuppies, honeymooners.

A note about shore excursions: Rather than getting into a long line aboard ship to sign up for organized tours, some passengers find they do just as well arranging their own trips on shore. You'll see independent tour operators, most of them reputable and generally offering more attractive rates. -- David Butwin