It’s five below freezing on the ice-caked surface of a lake in the French Alps and, as I prepare to slip, seal-like, into the black water, my racing mind is begging me to wimp out. Diving in a frozen lake at night – below ice, beneath the stars, at an altitude of almost 2,000 metres? What an absurd idea.
An hour ago, I was inside a tiny mountain refuge beside Lac Robert drinking tea, the temperature outside dropping by the second. Now, I’m outdoors and zipped into a cumbersome drysuit (designed to prevent water from entering), with blue latex gauntlets sealed at the wrists and a black frogman hood wrenched over my head.
Ice diving as a niche activity took off in the 1990s, offering an alternative adventure for thrill-seekers on their ski holidays. It’s available in two other French mountain resorts, Tignes and Val-Cenis. But here, above the village of Chamrousse where I’m staying, ice diving school Dive Xtreme has launched the region’s most intense, magical, low-impact thrill yet: a night dive in a frozen mountain lake, followed by a starlit night’s camping on its frozen surface amid 2,500-metre peaks.
Forget cold water swimming. This is the equivalent of taking the plunge under the north pole. The appeal, for me, is to get out of my comfort zone and experience what the instructors behind the idea, 25-year-old Thibault Dassieu and Tanguy Chamard, 30, describe as a chance to “connect both outwards to the wonders of the high-altitude landscape and inwards to the adventurer hidden within us all”.
As I wait in the deep snow, weight belts are slung over each shoulder and a heavy scuba tank lifted on to my back. Then a full-face respirator mask is strapped on tight. A gasket on my survival suit is opened, the air rattles out, everything tightens around me and the diving suit sticks to my skin. I shiver. I look like a cosmonaut; I feel like packaged ham.
The lake feels wild and secret, but it’s only a cable car and chairlift ride from Chamrousse, 20 miles south of Grenoble in Isère. The tiny resort in the Belledonne massif styles itself as an easily accessible base camp for micro-adventures and offers skiing, snowshoeing and snowmobiling, as well as short dog-sledding trips – and now ice diving.
Anyone can have a go – no experience is necessary, though divers must be at least 140cm tall and eight years old (the oldest so far was an 83-year-old grandmother). I’ve dived a few times, but this feels completely different – an opportunity to connect with nature in its rawest form. Looking down into the two metre-wide hole (cleft anew with an axe every morning), I take one last jolt of breath then we’re into the icy soup. Tanguy, all jokes and smiles, is relaxed. Me, nervous, almost paralysed. A pink line rips along the snow-covered horizon. “Now you’ll see why I’m addicted to this,” he says. As we vanish below, the world feels put on pause.
The first myth about ice diving is that it’s achingly cold. But with the lake temperature at around 1C, the surface is far colder and it feels like slithering into a tepid bath, though one with a snow-covered crust of metre-thick ice and an infused glow from the hazy surface torchlight.
The second is that it is risky. “When you scuba dive in the ocean, the danger is the depth,” says Thibault. “In Lac Robert, we’re a maximum distance of five metres from the ice and here the biggest issue is getting lost. This lake isn’t big enough – so it’s impossible.” A guide rope helps ease any panic, as do two additional emergency exits out of the ice. Fear remains though: some divers feel claustrophobic, others disoriented.
The gateway ice hole is a trap door into another realm. At first, I struggle to gain my buoyancy. Unlike regular diving, where scuba divers aim to float horizontally, the technique under ice is to remain vertical, with flippers pointed down and arms free to discover the rink above. The imperative is to empty all the air out of the drysuit. Otherwise, a jack-in-the-box bob results in a bump to the head.
We kick our flippers and our 10-minute loop around the lake begins. Lines of dimly lit ice curve away from me and through my mask I make out ribs of iced fissures and mutated crystals. In places the submarine ice has begun to thaw. Shapes appear and my mind stretches.
Tanguy turns entertainer as my eyes adapt to the dark. He lays a hand on the shelf above us and, as if by magic, passes me a torchlit sliver as part of a surreal, silent show-and-tell. Immediately it slips from my grasp, falling, spinning, fading into the abyss. He exhales deeply from his regulator; the result is an arc of bubbles that disperse and dance through my torch’s beam. Eerie, lurking crackles pop from above, echoing in the blackness.
Time slows in this magical, watery world. Tanguy twirls an index finger like a cocktail stirrer and a miniature tornado of loose ice spins and scatters into luminous shards and bubbles. I’m mesmerised. I feel I could hang out here for hours, but all too soon the dive ends and I am hauled back on to the snow by Thibault and an anchor rope. Now I look like a cosmonaut, but feel like a rescued whale.
That night, dried, changed, and our equipment defrosting in the refuge, Tanguy cooks fondue outside on a picnic table and the lake is transformed by the Milky Way. White wine is passed around. The pan of cheese is quickly emptied. Woolly hats are pulled down tight.
Eventually the stove is blown out. Soft snow begins to fall. I tread through the drifts to my tent on the lake. It is secured by threaded ice screws and snow-packed at the sides. I crawl into a down sleeping bag, the mountain silence interrupted by wind and what I imagine are burbles of ice and belching water below. The irony is a broken, restless sleep follows. I am too hot.
Around 7am, a thin mist creeps into the lake eyrie and croissants and coffee are served in the refuge where the instructors have slept. We wait for the chairlift tostart the journey back to the village, via the Croix de Chamrousse summit at 2,250m, chatting about our mad but memorable evening.
It’s one of those rare moments in life, I say, that seem to transcend the ordinary. When it’s possible to feel suspended, as if between life and death, all while haloed in a strangely brilliant glow cast from above. The pair nod. The mountain gods may have given them a frozen lake, but they have filled it with an adventure that feels almost not of this earth.
The trip was provided by Alpes Isère. A night dive with Dive Xtreme costs from €120 per dive, including all diving kit and instruction. An overnight bivouac costs €380 for two, including camping equipment, breakfast and dinner
