There's a scientific explanation for the amazing blue colour of glaciers and the various chunks of ice that break off of them; something to do with refraction of light and all that jazz. Frankly, I couldn't care less.
We are approaching the Endicott Glacier, which is rammed away at the end of the Endicott Arm, a 48-kilometre long sliver of water that extends inland in the puzzle of tributaries and slender waterways that make up Alaska's famed Inside Passage.
The water here is peppered with lumps of ice, some big, some small, some dirty, some as transparent as glass, some an almost luminescent, translucent blue.
Captain Pelle Fredriksson is on the bridge of the Norwegian Jewel cruise ship, threading a cautious path through this minefield of floating obstacles, some of which are as large as trucks and crested with resting seabirds. On one slender column I spy an imperious bald eagle on the lookout for prey.
Lounging indoor the NCL's Norwegian Jewel.
A crewman tells me that we are lucky; last week one of the glaciers hereabouts – possibly the Endicott but the actual culprit is unknown – broke off enough of itself to fill the waterway and make passage impossible.
I find myself fascinated by these little "calves", all these blues and azures and aquamarines and every shade between, all their gnarled shapes and smooth striations. They are at once exciting and calming.
Earlier in the afternoon I stood on my balcony, rugged up against the cold, to take photographs of … nothing. The landscape outside was a surreal miasma of water and light rain and mist and the shade of what I think was a small island. It was like standing on the edge of the world at the end of the world as it whimpered to a close – JMW Turner at his impressionist best but strained through the apocalyptic imagery of Cormac McCarthy's The Road.
Alaska's a bit like that, at least for this first-time visitor – a curious combination of the insubstantial, the surreal and the alarmingly down to earth.
It's a journey that didn't start like that. It started in warm sunshine in the immensely walkable city of Seattle, where I joined NCL's Norwegian Jewel for this week-long trip into the lower reaches of Alaska and back.
Kids splash out on deck.
Seattle sits on the edge of Puget Sound in the Pacific Northwest and, despite being Washington State's largest city, still retains a small town feel. It has good public transport options but is also an easy city to walk around. In just one afternoon I visited the Pioneer Square area, the waterfront at Elliott Bay where the cruise ships come in, the busy Pike Street markets (fish, fruit, trinkets, restaurants), and Space Needle Park, home to the city's most famous landmark. The little triangle of Westlake Park at 4th and Pike, by the way, is the place to go if you fancy a game of chess with a local or a bit of street ping-pong.
The Norwegian Jewel is not so much a cruise ship as the offspring of a threesome between a pinball machine, a gumball machine and an ocean liner. Its credentials are obvious from the sparklingly colourful imagery on its hull right through to the frighteningly funky orange and purple carpet in the cabins. This is not your elegant homage to the golden days of cruising, that's for sure.
The pool area on the Norwegian Jewel is a riot of colour.
Inside, the emphasis is on fun, fun and more fun – a raison d'etre that's echoed in the bright colour schemes throughout. Never have orange and blue been more effectively thrown together without causing a migraine. The carpets in the stateroom hallways are a deep blue decorated with golden fish that swim in the direction the ship's going and the cabin doors are painted a happy turquoise while the open-air swimming pool deck is a riot of colour circled by green and yellow lights in the shape of palm trees.
There's a shuffle board but thanks to the different demographic nobody looks like they are about to shuffle off their mortal coil anytime soon – traditionally a fear on some of God's floating waiting rooms.
Nope, it's like someone somehow squirted Bobby McFerrin's hit Don't Worry, Be Happy into a 3D printer and popped out a cruise ship.
Luxurious cabin fever.
But it's not all fun and games – there's some serious sightseeing to be done.
Our Seven Day Alaska with Inside Passage cruise sees us take off on Friday afternoon, heading north and spending Saturday at sea before pulling in to the towns of Ketchikan, Juneau and Skagway. After which we head south again and visit the old Victorian town of, er, Victoria in Canada.
Ketchikan, as with all our stops, is popular on the Inside Passage cruise route. Surrounded by the steep, snowcapped mountains and the cedar and spruce tree forests of the Tongass National Park, it's also known for its many Native American totem poles on display throughout the town.
Like Juneau and Skagway ahead of us it's one of those former frontier towns built on the blood, sweat and tears of the hardy and foolhardy men and women who carved out a living up here in the Alaskan wilderness.
One area near the mouth of Ketchikan Creek – known then and now as Creek Street – was a notorious red light district, with brothels lining both sides of the water. Today, like much of the town, it's full of souvenir shops selling everything from knives to gold nuggets and T-shirts proclaiming Creek Street as the place where salmon AND husbands came to spawn.
Salmon and timber were big business here in Ketchikan and, while the sawmills have fallen quiet, the fish industry is still going strong – not for nothing does it call itself the Salmon Capital of the World.
In Ketchikan I opt to join a tour which takes in a rollicking lumberjack show and a bus trip out to the Saxman Native Village on the edge of town. The lumberjack show is great ra-ra, boo-hiss fun and the village visit provides an insight into the life of the indigenous people. We also meet local artist and totem pole carver Nathan Jackson in his workshop.
Other passengers who went on a wilderness cruise came back with tales of orcas, whales, dolphins, bears and bald eagles. This, I realise, is the secret to successful shore days. Ketchikan, Juneau and Skagway, while beautifully preserved and/or renovated, are mere shadows of their former down-and-dirty pioneering selves. This is souvenir and jewellery shop heaven. If you want to buy a mind-altering, Technicolor 3D grizzly bear placemat, beaver 'poop' sweets, faux gold nuggets or moose nativity box set ($29.99 plus tax) they are the places for you but it's a far cry from Klondike gold rusher Jack London's Call of the Wild.
The real excitement comes in the shore excursions on offer. A morning at a husky camp was a doggy delight and included a short but exhilarating ride with a 16-strong Alaskan husky team and a chance to pet both the working animals and a quorum of pups. And if I had my time again I'd eschew the Skagway Street car tour for a helicopter ride around the area in the hope of spotting a bear that you can't stick to a fridge.
Qantas, United Airlines, American Airlines and Delta Airlines fly from most major cities direct to Los Angeles and San Francisco. From there, you can then get a connecting flight to Seattle. NCL advises booking these as a through flight on one ticket.
NCL's Norwegian Jewel will be plying the Inside Passage route until late September when it will begin a 49-day cruise from the Inside Passage to Sydney via Hawaii, French Polynesia, Vanuatu, American Samoa and New Caledonia.
When it arrives in Sydney on November 12 it will begin a season around Australia and New Zealand. This includes a five-day return cruise to Tasmania from about $719 per person and a 13-day Australia and New Zealand cruise taking in Melbourne, Burnie, Wellington, Napier, Rotorua, Auckland and the Bay of Islands. Visit ncl.com for more details and prices.
Keith Austin was a guest of Norwegian Cruise Line.