Deep Freeze

Adventures of an old, cold diver

There’s a well known cautionary aphorism that goes: “there are old divers and bold divers, but no old, bold divers.” At age 51, I definitely belong to the former category, but am a little less certain about the latter. I was struck with this self examination as I sat with my fins dangling through a triangular hole in two feet of frozen lake ice. The air temperature hovered near zero degrees Fahrenheit, the water barely above freezing, but at least enough to be in a liquid state (pro tip: it’s warmer the deeper you go). I’d been diving under the ice before, but that was in my relatively more youthful mid-40s. Now, after some last minute cold-related equipment issues, it was my turn to slip under the ice.

For most people who live in northern climes, the thought of scuba diving in winter typically conjures a plane ticket to someplace humid. I’ve done that—Mexico, Bonaire, Sri Lanka—but there’s a more affordable and unique option closer to home: ice diving. Mention the idea to most people, even seasoned divers and it’s usually met with incredulity. Claustrophobia and cold are the typical barriers to considering this niche pursuit. Fortunately, I fear neither. I’ve crawled through cave passages beneath the Belizean jungle that require an inhalation to fit, penetrated inside deep shipwrecks, and enjoy the challenge of skiing and hiking in even the coldest of winter windchills. So diving through a hole in the ice isn’t so much about bravery or ignorance or sheer madness. It’s about the right equipment, the right partners, and the right skills.

Winter here in Minnesota is long. Very long. It descends in November and lasts pretty well through the end of March, sometimes beyond. That’s five months, almost half of a calendar year, and if you don’t find interesting, stimulating diversions, you’re going to be miserable. I’ve been a lifelong cross-country skier, have winter camped, get excited by snowstorms, and deep cold is just an excuse to feel smug, swaddled in 850-fill down. Five decades of winter living and I still have a sense of wonder at the beauty of a landscape that is covered in a white blanket for months on end, how the birds and squirrels survive, and how a car will start at minus 20. I realize this isn’t for everybody. If you complain about the cold or wait for perfect weather to go outside, you’re probably better suited for someplace several hundred miles south.

I love challenges and stretching my comfort zones. Winter is one long challenge, especially when you do things more commonly associated with warmer conditions, like bicycling, cooking outside, or scuba diving. To do even the most basic of these activities in February, without drama or fanfare gives a satisfaction that far outweighs any hardship or discomfort. So, while a day of shoveling a frozen lake, anchoring ice screws, thawing a frozen inflator valve with numb fingers might seem unpleasant, the smug feeling when I’m back home in the evening with a whisky and my slippered feet up by the fire is immeasurable. Most people who drive by Square Lake, peering out of a warm car, see an expanse of white with a few ice fishing huts on it. I know what the bottom of the lake looks like. But when ice diving, the interesting view is above you.

Decomposing plant matter on a lakebed emits bubbles of methane and other gases constantly, but in small quantities. Put a few divers underwater though, exhaling liters of carbon dioxide and it’s a lot of bubbles that have nowhere to go if there’s a two-foot thick ice sheet on top. So one of the necessary tasks before going under is to augur air escape holes in various place. This gives the exhaled air bubbles somewhere to go besides through the main entry hole, where it can be inconvenient, cold and very wet for the rope tender and safety diver. The resulting vent holes become violent geysers, erupting with plumes of water at irregular intervals. From underwater, the view upwards reveals the amorphous blobs of air dancing around on the underside of the ice sheet, seeking a way out. Backlit by the penetrating sunlight, these massive forms appear like dark phantoms, almost alive, desperately clawing for their freedom. 

Another pre-dive topside task is to clear snow in a series of guidelines that radiate out from the entry hole. Seen from underwater, these lines, with appropriately shoveled arrowheads, allow more light to penetrate the snow cover, revealing a bright pathway back to safety in case a diver becomes disoriented or detached from the safety rope. Nature rarely produces straight lines and right angles, and these stripes in such an alien environment are both reassuring and fascinating. The underside of the ice also reveals fissures and pressure cracks from the freeze/thaw cycle of a long winter and the shifting of the ice. Sound carries well underwater and between the roar of exhalations, you can hear the lake ice sheet booming and cracking above you as you swim the 100-foot radial arc of your dive.

The term “overhead environment” is used by divers to refer to anything that prevents access to the surface. This can be something obvious like the inside of a shipwreck or a cave, but can also be an invisible barrier, such as a decompression stop that must be held at a particular depth before one can safely return to surface pressure. In my years of diving, I’ve never had an emergency that necessitated an unscheduled ascent to the surface. I’ve had a mask seal tear underwater, buoyancy issues, even run out of air, but nothing that couldn’t calmly be dealt with at depth, followed by a controlled and patient return to the air and light above. But I won’t pretend that while diving under ice, far from the exit hole, the thought doesn’t creep in that, should something go wrong, escape isn’t as simple as going up. My ice dives have never been deeper than 30 feet (around 10 meters), a depth that in a normal open water diving scenario would present an easy and safe exit. But when the only way out is 100 feet away, you tend to pay more attention to your gear, your air supply, and the behavior of your dive partners.

The other spectre of ice diving is the cold itself. The relative discomfort of water temperature barely above freezing can be largely mitigated by the right gear—thick polarfleece thermals, multiple pairs of woolen socks, a 5mm hood, fitted rubber dry gloves, even chemical toe warmers. But what the cold can do to gear is a constant concern, leading to an OCD-level of checking and rechecking for hissing connections and frozen valves. Before my dive on Saturday, I held my ear to the tank valve, diagnosing a slight hiss of air. With numb fingers, I loosened my regulator connection, changed the rubber O-ring inside, retightened. Still hissing. Changed second stage hose and mouthpiece. Still hissing. Hands getting colder. Finally, I changed tanks entirely. The hissing stopped. Seals contract inside cold steel, lubricants get thick. Valves stop opening, or closing. Should a regulator stick open, an 80 cubic foot tank would gush out in little over a minute. How fast can you swim 100 feet under ice to the safety of the only exit?

When I dropped through the hole into the water, I immediately became aware that I was underweighted. Layers of fluffy insulation inside a suit filled with air, not to mention a large camera housing, was keeping me pinned to the underside of the ice. I came up through the hole for more weight, which a tender clipped to the top of my tank. Hot water was poured over my drysuit’s vent valve to ensure it would open and release air trapped inside. Finally, I was able to descend, my camera lights’ arms getting tangled in the safety line. I landed on the lake bed with a poof of silt. My arm went in beyond my wrist. I got my bearings and regained a semblance of buoyancy, feeling every bit a novice. Turns out ice diving is like any specific pursuit—neglect it and the skills wither. But it’s not exactly something you can practice very often.

Ice dives are generally short, mainly due to the cold. Mine was all of 25 minutes and by the time I climbed through the hole back to the land of the living, my lips were too numb to even thank the rope tender. Not too numb to smile though. It’s a lot of work—hours of shoveling, erecting a tent, cutting holes, prepping gear— for little time underwater. Every time I do it, I vow it will be my last. But then I come home, warm up, and study the photos from the dive and I’m reminded of what a privilege it is to do something so incredibly unique. It’s an extreme adventure played out under the ice of a lake close to home, an experience I share with only a few others and have difficulty relating to those who will never do it. I’m not sure I fit the description of an old, bold diver, but I’m definitely an old, cold one.