Pinnacle of adventure

David Whitley explores the beauty of New Zealand's Mount Cook region and takes us with him on Tasman Lake as he navigates icebergs.

A hike to Tasman Lake offers much to see, from snow-capped mountains to lakes and waterfalls. Photos courtesy David Whitley

Even with the mist covering the tallest of them, the mountains rising up around the Hooker Valley have a humbling stature. They shoot up intimidatingly and are virtually straight (and unclimbable), the result of the tectonic grinding that has given New Zealand its "Shaky Isles" nickname.

The glaciers in front once covered the valley floor, but an indication of just how hostile they are comes from the journey time to the more famous Fox and Franz Josef glaciers on the other side of New Zealand’s tallest peaks. They’re only a few kilometres away – highly experienced mountaineers have walked it in less than a day – but to get there by road requires a detour of at least five hours.

The position of the Southern Alps has long made them a tricky training ground for pioneering mountaineers. Many of the 3,000-metre-plus climbs are technically difficult, but an element of danger is added by the notoriously changeable weather.

Once over the top, it’s pretty much a straight drop down to the Tasman Sea – and the fronts blowing in from there add a tempestuous maritime climate to the height and unflinchingly steep gradients.

On one of those wet, gale-wracked days, it’s worth dipping into The Hermitage Hotel – which has provided shelter for explorers in Mount Cook Village since 1884. It’s home to the Sir Edmund Hillary Alpine Centre, named in honour of the man who, along with Sherpa Tenzing Norgay, became the first to scale Everest.

The museum section is partly about the history of climbing in the area, and partly about Hillary himself. He was a New Zealander and much of his love of climbing came from tackling the Southern Alps in the 1940s. He was in the first party to summit Mount Cook – the tallest of them all – via the previously untamed southern-ridge route. And he used the area extensively when training for his other missions. These didn’t stop at Mount Everest. He also piloted a jetboat up the River Ganges in India from mouth to source, and crossed Antarctica overland via the South Pole – the first expedition to reach the South Pole by land since Robert Falcon Scott’s ill-fated party in 1912.

The photos from the training for that Antarctic crossing, in particular, are mesmerising. Hillary is often clad in ridiculous woolly jumpers, getting to grips with the specially converted Ferguson tractors he’d make the crossing on, or upgrading his skiing and dog-sledding skills on the Tasman Glacier.

In comparison to Hillary’s feats, hiking through the Hooker Valley, for me, feels very much like baby steps. Boardwalks traverse marshy areas turned into impromptu streams, while the mountainsides turn into giant water features, dozens of waterfalls springing from them and gushing down the rock faces.

A series of swing bridges are traversed, then the track continues along open ridges until the first sighting of Hooker Lake – which is likely to be one that sticks in the memory. Icebergs, often a brilliant blue, float across it in front of the huge rubble-strewn slopes carved by the glaciers.

It is not the only lake strewn with icebergs in these parts. And perhaps the most incredible thing about Tasman Lake is that it didn’t exist 25 years ago. It has been created by the rapid retreat of the Tasman Glacier – which has shrunk by about six kilometres in that time – coupled by avalanches that have diverted streams.

Standing by the shore, helping to unload the kayaks, I ask Glacier Kayaking’s guide, Mark, how long we’re likely to be out on the water. “Well,” comes the reply, “it kinda depends on how excited Charlie gets by the icebergs.”

Charlie Hobbs has been guiding kayaking, hiking, heli- skiing and climbing tours around Mount Cook for decades. He has been there to see Tasman Lake become what it is today from a few puddles, and he stills sets out on it with unrestrained glee. Despite his reminders of what happened to the Titanic – "That was made of tons of steel; what you're paddling is made of plastic. Don't crash into the icebergs" – he throws his kayak at them with joyous relish.

There’s a purpose to the carefully planned attacks. He launches his kayak at the least steep edges of the bergs in a bid to show them off properly.

The frosted white ice of what lies above can quickly turn to startlingly transparent or siren-like vivid blue ice as the sub-aquatic sections are brought forth.

When ramming the icebergs doesn’t work, he opts for a different approach – lopping great big chunks off with an ice pick. This might look like mindless vandalism, but once the icebergs have broken off from the glacier, they don’t have long to live. The water may be chilly by our standards – it never really gets higher than about 3°C – but it’s enough to slowly doom the ice over a couple of weeks.

Hacking a section of the iceberg off changes the centre of gravity, and slowly sends it into a spin until it finds a new balance. Again, pristine sections from below rise to the surface, revealing a monster that’s much larger than it initially looks.

In truth, the icebergs we are sidling up alongside are relative tiddlers. They seem enormous while at water level in a kayak – although they’re maybe five- metres tall.

At the other end of the lake, however, they can be up to 50 metres tall, with a good couple of hundred metres more drifting below the surface. They break off an ice shelf that is simply too dangerous to venture near. Luckily, the wind gradually blows the bergs down to the end of the lake like stricken ships.

On the paddle back to the shore, there’s more chance to take in the surroundings. The ring of snow and glacier-covered mountains is broken only by the river gushing out of the bottom of the lake. The moraines dumped by glaciers look like untraversable rubble slides. The lake is an eerie, dazzling, milky blue, as if someone has tipped fairy dust into it. And two of Mount Cook’s three peaks protrude a good couple of hundred metres above everything else on the horizon. Humbling doesn’t even begin to cover it.

Head east from the highest peaks of the Southern Alps, and you end up in the Mackenzie Basin, a sparsely populated region of barren-looking tussock grass, merino sheep ranges and ever more fairy-dust lakes.

The lack of human interference makes for incredibly low levels of light pollution, and this gets astronomers excited. The region is the world’s largest International Dark Sky Reserve – a somewhat inaccurate name, given the whole point is that you can see what’s twinkling in the sky with almost unbeatable clarity.

Some stargazers, however, get a bit of extra help. The Mount John Observatory, high on a hill above Lake Tekapo, is home to some of the most powerful telescopes in the world.

The telescopes, covered by giant domes, are peering unfathomable distances into both the universe and the past, honing in on stars that are billions of light years away from Earth. Of these, the largest is the MOA and it looks very much like an evil Bond villain’s deadly laser weapon. Its task is to scan the most densely star-packed sections of the sky, looking for changes in light patterns that could indicate the presence of exoplanets orbiting distant stars.

If we find life in the cosmos, this will probably be the starting point. Until then, the highlands of New Zealand’s South Island are about as otherworldly as it’s possible to get.