We're cruising through a long, narrow fiord in southeast Alaska, as granite cliffs soar skyward and the sun splatters diamonds across the water. This, they tell me, is merely the overture.

I am seated comfortably in the wheelhouse with the captain and a half-dozen other passengers, the panoramic view unfurling before us. We've got box seats for the performance.

We round the bend. Brilliantly blue and appropriately massive, LeConte Glacier looms in the distance. But ahead an ice field blocks the way. Scattered across the ice slabs are hundreds and hundreds of what look like sausages. Seals, the captain says, but what else he says is lost on me: I rush to the lower deck for a closer look.

"Keep a hand on the rail," the announcement comes over the loudspeaker as we clunk through bergs the size of a bus, "and hold onto your cameras."

The seals seem to know they are safe from killer whales here, and our slow-moving craft is obviously not a threat. Some of those closest to the ship reluctantly give up their sunning and slide into the sea. Others simply eye us bemusedly. They know whose territory this is.

Arctic terns wheel above. The ice ahead looks solid, but we plow our way purposefully through it -- thunking, grinding and zigzagging toward the jagged blue wall ahead. We nudge an impressive berg, which does a slow roll to reveal an elegantly carved crystalline underside.

Slowly, our ship, the Sheltered Seas, cruises the mile-wide face of the glacier. We are told its astonishing blue color is due to a light trick. Ice molecules absorb all the colors of the spectrum except blue, which is reflected back. Light trick or no, this is the bluest blue I have ever seen.

From front row center I run my eyes back and forth across LeConte's vast, craggy expanse like a video camera, intent on capturing forever its majestic presence. The wind is fierce -- perhaps it foreshadows even more wild beauty.

I am offered champagne or sparkling cider to toast the continent's southernmost tidewater glacier. But of course: If ever a production were worth celebrating, this is it.

Someone else must be steering our ship, because the captain appears at the bow, his glass (of cider, our designated driver quickly assures us) raised high. At that exact moment, the glacier explodes thunderously, sending a giant mountain of ice crashing into the sea.

Everyone cheers. The captain urges us to hang onto the railing. For a brief moment he has violated a cardinal rule: Never turn your back on a tidewater glacier. Not to worry. Our boat rides the swell unleashed by the avalanche like an old salt.

The show is not over. LeConte takes its role of disgorging icebergs into the bay (a process known as calving) seriously and is considered one of Alaska's most active glaciers. After a half-dozen such feats, we leave the glacier to continue its performances for an audience of eagles, seals, mountain goats and the occasional bear.

We have to leave, the captain says, because there are theatrics ahead we don't want to miss. Nothing could top this, I think, but then, I'm a full day away from having a humpback whale rocket out of the sea right in front of me.

Talk about show stoppers: Southeast Alaska has them in abundance. We have chosen the ideal way to participate in this ruggedly beautiful wilderness.

At 90 feet, our good ship, the Sheltered Seas, is small enough to afford its 90 passengers the best seats in the house. At one point the captain maneuvered so close to a waterfall we could lean over and fill our glasses with pure ice water.

Our route follows the shoreline -- an intricate maze of islands, inlets, coves and fiords, that are all part of Tongass National Forest, the largest National Forest in the United States. We pass Admiralty Island National Monument, which is the home of more than 1,000 coastal brown bears and features the highest concentration of bald eagle nests in the world. The captain is tuned in to nature and welcomes the opportunity to "go play with those whales over there" (carefully avoiding harassment of these gentle giants) or to follow a river to an eagle's nest.

All cruising is done during daylight hours, with time allotted for extemporaneous wildlife viewing. Instead of sleeping aboard, we stay overnight at comfortable fishing lodges or shoreside hotels at Inside Passage ports of call. This gives us a chance to explore the colorful communities on foot.

We spent three days navigating the 350-mile waterway between Ketchikan and Juneau, a stretch considered the most spectacular portion of the famed Inside Passage -- yet covered by most large cruise ships in a single night.

In Ketchikan, we visited Totem Bight State Historical Park, a replica of a Tlingit Indian settlement complete with a community house and a fine collection of totem poles (Ketchikan has the world's largest collection of totem poles) before boarding the Sheltered Seas. The name Ketchikan, by the way, is derived from a Tlingit word meaning "the salmon creek that flows through town"; in late August that creek was bank-to-bank full (so packed you could not see the water for the fish) of migrating salmon.

We then cruised to Wrangell, an untouristy fishing and logging community, where we visited a native lodge house and learned more about totem poles on Chief Shake's Island. During our two-night stay in Petersburg, a fishing village with many inhabitants of Norwegian descent, we browsed through the local museum and devoured a traditional smorgasbord dinner while watching nimble-footed Norwegian folk dancers.

In Petersburg, passengers were given a choice of five optional shore excursions, which included touring this "Shrimp Capital of the World" with a lifelong resident, seeing LeConte Glacier by a ++ small plane or helicopter (including a landing on the ice field), a charter fishing trip or a commercial trawling adventure. As seafood aficionados, we chose the trawling adventure and were rewarded with the most succulent crab and shrimp (tossed directly from the nets into boiling water) we've ever had the pleasure of consuming.

After viewing the LeConte Glacier, we cruised north to Frederick Sound, summer playground for humpback, minke and killer whales. The humpbacks were out in force -- spouting, breaching and cavorting about the boat, then exiting with a grand finale, a magnificent display of their enormous tails.

A memorable cruise into Tracy Arm, one of Alaska's most dramatic fiords and a close-up look at Twin Sawyer Glaciers preceded our entrance into Juneau, Alaska's capital hunkering in the shadow of towering Mount Juneau. There we strolled the historic district, listened to gold rush tales and drove right up to the Mendenhall, Juneau's drive-in glacier.

The final curtain of our Alaskan experience was a gold-and-salmon sunset that gilded Juneau's Gastineau Channel and made the clouds above it glow from within. The performance was entirely satisfying, no encore was needed -- at least not for another 24 hours.

If you go . . .

Southeast Alaskan summer temperatures generally range from the mid-50s to the mid-60s, although they can reach 80 degrees on a sunny day. Weather tends to be quite changeable but prepare for mostly cool, moist days with overcast skies. June is usually the driest month and October the wettest.

Pack warm, comfortable, casual clothing, including layers (sweaters, rainproof jackets) and light summer apparel.

Definitely have sturdy walking shoes, and you might want to consider bringing thermal underwear, gloves and a cap. Bring a small bag for the gear you may want each day on board, as a suitcase probably will not be accessible.

Be sure to bring sunglasses and binoculars, and a camera with telephoto lens and polarizing filters.

A five-day cruise-tour with overnight accommodations, sightseeing and transfers in Ketchikan and Juneau costs from $795 to $1,295, depending on the season. (Cruises operate from mid-May through late September.) Optional shore excursions are extra.

Ask a travel agent about Inside Passage Yacht Tours, or write Alaska Sightseeing Tours, 700 Fourth and Battery Bldg., Seattle, Wash. 98121; telephone (800) 426-7702 or (206) 441-8587.

Excellent books to read in preparation for the trip:

"Alaska's Southeast -- Touring the Inside Passage," by Sarah Eppenbach (Globe-Pequot Press).

"Travels and Alaska" and "Northwest Passages," both by explorer/naturalist John Muir (Houghton Mifflin).