Only 10 passengers are up on deck, but each stands hypnotised by the vision of this sub-zero sanctuary.
Alaskan Dream, smaller than the Manly ferry, has prime position in front of a skyscraper- high glacier, with not another ship in sight.
Our native Alaskan expedition leader, Kevin Skeek, points out the place where the kilometre-wide mass is most likely to calve.
We believe him - his Tlingit name is Kaadushtoo, which means "the breaking of the glacier". Passed down from former leaders of his clan, it is also the name of one of the hanging glaciers in nearby Johns Hopkins Inlet.
Aged 30, Kevin is next in line as the head of the Chookaneidei clan of Hoonah. His ancestors lived here, in Glacier Bay, about 12,000 years ago until they were pushed out by the Little Ice Age of the 18th century.
According to stories passed down to him by elders, an aggressive glacier moved "at the speed of a running dog", crushing villages in its path as residents fled in canoes.
"The blood that has defended, cared for and witnessed the last 12,000 years of Glacier Bay pumps like the rhythm of a sealskin drum through my veins," Kevin says. He shares his experiences and cultural knowledge throughout our cruise so we can appreciate that his homeland is much more than beautiful scenery with exciting moments of glacial action.
Nevertheless, when the calving happens, which is several times in an hour, we are thrilled by the thunderous commotion. The blue ice groans and crackles as a huge piece snaps off and plunges into the bay, shooting water hundreds of metres into the air.
Watching nature at work, creating an iceberg, is a privilege. Calving is so regular that an American couple on board say they can see a difference in the landscape since visiting only four years ago.
Howard, or Koo Hook, from the Wooshkeetaan clan, is the ship's other native expedition leader. He tells me he prefers the Tracy Arm region because the coastline is more dramatic.
"At a spiritual and ancestral level, Glacier Bay is the place that speaks to me, but in terms of sheer awe, Tracy Arm stirs up a heavier reaction," he says. "It makes me look at the extremes that the Tlingit people had to endure, whether it was hiking these cliffs to get goats or navigating this waterway to find seals."
His smiling face glows as he speaks about this frozen haven, and his enthusiasm livens up the atmosphere on board. After glacier-gazing, passengers sit with him in the ship's lounge in order to glean more information.
Launched in 2011, Alaskan Dream Cruises has made a point of employing indigenous crew and guest speakers from the south-east of the state.
Also on our voyage is Teri Rofkar, one of the few remaining Tlingit weavers and a self-described "basket case", who gives daily presentations on her craft. Her intricate baskets and ceremonial robes are made of natural materials collected, with much difficulty, from the local area.
Teri speaks so passionately about picking goats' wool from carcasses or tufts snagged on tree branches (she never takes it from a living animal) that I find myself staring into the mountains straining to spot a speck of white standing on a ledge.
The line's owners, Bob and Betty Allen, are themselves members of the Kaagwaantaan clan, and their children and grandchildren now run the company. After 40 years operating jet-boat day tours, they decided to offer their own weeklong cruises, visiting places that only locals know.
The itineraries are designed to steer clear of the 3000-passenger superliners that dominate Alaska, and on several days, we don't see anyone else.
We do, however, see a lot of whales, harbour seals, sea otters, bald eagles, puffins, kittiwakes and bears.
Rather than boarding in a busy port, the trip begins in Sitka, a salmon-fishing community with a strong Russian influence.
As the former capital city, Sitka was where Russia sold Alaska to the US for the bargain price of $US7.2 million in 1867.
This history, and the controversial fur trade of the time, is worth exploring in the town's museums.
Official proceedings kick off a little differently to the average cruise. On the morning of departure, a crew member meets each passenger at the airport or hotel, while their luggage is transferred to their cabin.
Everyone gathers at a clan house for afternoon tea and a traditional performance by the Sheet'ka Kwaan Naa Kahidi dancers.
Then passengers are taken on a wildlife cruise, which connects with the Alaskan Dream, where the captain welcomes guests on board for champagne and canapes.
With fewer than 40 passengers, mingling happens naturally. In the mix are Australian, American and British couples in their 50s and 60s, a woman travelling solo, and a family of grandparents, a young mother and her son. At each meal, we switch tables to meet new people, and we chat every night during happy hour.
One evening, Ernie the bartender mixes "Bergy Bit" martinis using crushed pieces of glacial ice, which the crew has scooped out of the water. It's the ultimate example of the authentic (and very refreshing) Alaskan experience provided on board.
The lounge-bar faces forward, enveloped in wraparound windows that display the same view as the captain's two decks up.
Contrary to the policies of most cruise ships, we are allowed to visit him in the bridge for a peek at the controls.
I watch as he smoothly spins the vessel 360 degrees to give us the full panorama of the twin Sawyer glaciers. At another point, he pulls up so close to a pounding waterfall, anyone on deck is sprayed with mist.
A thrilling highlight comes on the day our ship is encircled by a pod of humpback whales being chased by a couple of killer whales. But we are just as tickled by the sea otters floating on their backs, and the hundreds of seals chilling out on individual icebergs.
My favourite port is the almost-unknown Hobart Bay, to which Alaskan Dream Cruises has exclusive access. The glassy water, which shimmers in silver under the cloudy sky, reflects the mountains and rainforest. Best of all, we have this entire playground to ourselves overnight.
Passengers of all ages spend the afternoon kayaking between beaches and zipping around on Zego runabouts (like large jet skis that keep riders dry).
At dusk, we watch a mother bear and her cubs splash in the stream to catch fish. The white-gold sunset is all the more superb as it comes after three days of rain.
In the morning, I get behind the wheel of an ATV (all-terrain vehicle) and follow a guide around old logging roads. Everyone tries at least two activities, encouraged by the fact there's no extra charge.
Another private port of call is the waterfront Orca Point Lodge, again reserved for Alaskan Dream guests. Cooking outdoors, the chef serves salmon fresh off the hot plate and then surprises us with a feast of king crab.
John Martin, a fluent speaker of the Tlingit language, and his wife, Carolyn, join us to share their stories, which continue after dinner around a log fire.
Howard tells me there is an art to Tlingit storytelling, and children are raised to sit quietly and listen for hours. "We don't have photos or footage of our grandparents, so elders are our only window into our past and our identity," he says.
"For visitors, it's a way to understand how native people view the land and to connect with their surroundings on a deeper, even spiritual, level. I believe that's an opportunity that's severely lacking for visitors to Alaska, and it should be afforded to everyone."
The writer was a guest of Alaskan Dream Cruises.
Cruising there: A nine-day Inside Passage cruise aboard the 42-passenger Alaskan Dream is priced from US$3339 ($3992) a person (twin share, outside cabin), including all activities, airport transfers, meals and a complimentary wine or beer with dinner. Free shore excursions range from bear-viewing hikes to visits to the Sheldon Jackson Museum and Russian Bishop's House. A three-hour jet-boat ride down the sublime Stikine River is also included.
This year's season runs from May until August.
More information: smallshipadventure.com, email firstname.lastname@example.org.
A cool change is coming
This year, Alaskan Dream Cruises will introduce a new vessel, the Baranof Dream, operating a new 11-day itinerary focusing on the smaller communities of south-east Alaska. This expanded trip adds three days of scenic cruising around eastern Chichagof Island and Baranof Island, Point Adolphus and Red Bluff Bay, depending on weather and wildlife sightings.
Departures in May, June and August sail round-trip from Sitka, with calls at Juneau, Petersburg, Kake, Skagway and the company's exclusive Orca Point Lodge and Hobart Bay. Rates start at US$2245 ($2684) (twin share, inside cabin), $4470 (outside cabin, twin share) including all activities, airport transfers, meals and a complimentary wine or beer with dinner. Alaskan Dream and the larger 66-passenger Admiralty Dream sail via Sitka or Ketchikan on itineraries ranging from eight to 13 days.
- The Age