STANDFIRST] Summer cruises are popular in the Arctic, but what about winter? Sarah Marshall braves minus 30C temperatures to embark on a pioneering voyage through the ice.

Floating perilously on a wafer-thin diamond of ice, a coil of slashed and scarred blubber drifts into the blackened harlequin sea. Skin saggier than a deflated balloon, he rasps and snorts hot air through frozen whiskers, like a knackered set of bellows stoking a fire unlikely to ignite.

Cute? Hardly. Cuddly? Certainly not. But there's something pathetically endearing about the aesthetically-challenged walrus, one of the many species struggling to survive in the Arctic.

Anyone watching Attenborough's Blue Planet II can't fail to have been tear-jerked by scenes of a mother bonding with her young as their habitat melts away.

During summer, when most expedition cruises visit Svalbard, the Arctic archipelago curving the earth's peak at 78 degrees north, it's common to see herds of walrus hauled out on beaches.

But to find them in their preferred environment, when extended sea ice creates a frozen kingdom, requires effort; braving mercury-plummeting temperatures and gnawing winds, very few people are prepared to venture into the relative unknown.

In 2016, WildPhoto became the first operator to offer winter cruises in March and April, ahead of the standard season which kicks off in June. Up until that point, only researchers were out on the water during those months.

"It took us a year to obtain the permits," explains Roy Mangersnes, an acclaimed Norwegian wildlife photographer who runs the business with his friend Ole Jorgen Liodden.

The pair, who also have an art gallery in Longyearbyen, Svalbard's tourist hub, are dedicated conservationists and campaigners with a string of photographic awards between them. Their portfolio of trips, which includes Antarctica, Alaska and Greenland, has been developed to create optimum opportunities for photography without causing distress to wildlife.

Although not members of the Association of Arctic Expedition Cruise Operators (suggested distances for bear encounters proved a sticking point) their eco credentials are strong.

Weathered but sturdy, as any good sea maiden should be, our vessel for the eight-day Svalbard voyage is Swedish-built M/S Origo. The set-up, though, is not entirely utilitarian. Filled with superfluous mid-century furnishings - a Welsh dresser stacked with well-thumbed paperbacks and a piano topped with candelabras - the ship's interior is delightfully charming.

Although the Origo is capable of carrying 24 passengers, WildPhoto only take 12 on board, giving us plenty of space to shuffle around the snow-dusted deck and two upper levels.

Setting off from Longyearbyen at 4pm, we glide into a burning sunset that lasts for hours. Scarlet flames lick mountain peaks and singe streaking clouds, although any sense of heat is illusory.

Wrapped head to toe in multiple layers, I'm peering through a woolly pillar box, and my lashes are frosted together as if I've just awoken from a cryogenic deep sleep.

"Count yourself lucky," shivers Erik Gronningsaeter, our guide for the trip. "It was minus 30C out here last week."

That night, after leaving the shelter of Isfjorden for the open Greenland Sea, a patch of rough water sends us tossing and tumbling like rags in a washing machine; one disadvantage of bona fide icebreakers is a lack of stabilizers to steady the ship's motion. So, we change direction and hug the coastline of main island Spitsbergen toward the frozen northeast corner.

Unlike the crowded summer period, there's no need to book landing sites, so our adventure can develop as the captain sees fit.

A foggy sun casts bitter lemon rays over the fragmented, sepia-tone icescape, and plumes of sea smoke fuddle the horizon. Determined not to disrupt the environment, our captain kills the engine and we stop at the ice edge, where a pile of frozen rubble stretches until what appears to be the end of the world. The scene is deceptive.

On the whole, there's less ice than ever in the Arctic but wind is pushing a large amount over to Svalbard this year, explains Erik, making it harder to access fjords and find polar bears. This ice is also worryingly thin.

"Svalbard bears will probably disappear in five to 15 years' time," predicts the trained zoologist, ominously. "There'll be nowhere left for them to go."

Despite hours searching through binoculars on the bridge, not one buttery blob has been sighted. At Smeerenburg, we do spy a hulking marine mammal walking nine kilometers away, but sadly not in our direction.

We're particularly unfortunate; on last year's three winter trips, multiple bears were seen.

Returning south, we wedge ourselves into the ice at Magdalenefjorden and anchor for the night. It's a site I've visited several times in summer but right now, clothed in winter wear, it appears completely different.

Raging reds relax into calm pinks and blues as the tide heaves and sighs into a deep sleep. Veiled by cloud, flocks of ghost birds swirl through the sky, and when the wind drops, a silver moon is perfectly reflected in the metallic, viscous water.

Light is one of the main reasons to visit the Arctic at this time of year, when darkness never truly falls, and dusk segues neatly into dawn.

A palette of ever-changing pastels and eery hues, it dresses everything in a mystifying glow. "You're missing the best bit!" I think smugly, as everyone else slips off to bed. Better than any aurora display, it keeps me up all night.

All voyage I've managed to avoid wearing the clumsy survival suits we're required by Norwegian law to carry, but on a Zodiac (inflatable dinghy) trip at Kongsfjorden, there's no escape.

It's a wonder the wildlife isn't terrified by my neon onesie and gimp mask get-up, but a family of walrus seems unperturbed.

The lumbering pinnipeds give birth in winter, so it's not surprising to find a new arrival comfortably concealed between folds of ice. A guard male raises his sabre-sharp tusks defensively as we drift past, although I suspect he'll be confronted with greater challenges in the months ahead.

The trill of returning little auks spells spring is on the horizon and this icy kingdom will soon sink back into the sombre sea.

Every season in Svalbard looks different, that's the beauty of the destination, and no two scenes are ever the same. But if too much change is alarming for transient visitors like us, it's devastating for the permanent residents - no matter how unattractive they might be.

How to get there

WildPhoto (wildphoto.com) have two eight-day Svalbard winter cruises in 2019, departing on March 18 and April 11. Prices start from $7,295 (£5,493) for a twin cabin with shared bathroom, including all meals and activities and rental of a survival suit. Flights extra.

For more details on the destination, go to visitsvalbard.com and visitnorway.com