North Cascades. Alpine Guide Exam. Day 8.
I led my rope team of Miles Smart and Steve House across the Inspiration Glacier in a thick October fog. In 70-foot visibility I wound through crevasses, often glancing at my map and altimeter, and back at the black slots. I descended to 7,440-feet and contoured around crevasses until our tents emerged from the murk 50 feet away. Our rope team was the first back to camp. The other teams were still high on Eldorado Peak, making slow progress while squinting at the arrows on their GPS units.

The core of whiteout navigation is your map reading and terrain reading skills. You hone these skills by running around in the mountains with a map in your hand. Before your tour, study large-scale (detailed) maps at home or camp to visualize and understand the terrain. Develop a tour plan with a sketched route, hazards marked, distances, elevations, and times. While on the tour, keep the map folded to your region, placed in a Ziploc bag, in your pants pocket, so it’s accessible for continuous glances.

Since mountains are three-dimensional, altimeters, such as the Suunto Altimax, are the second most important navigational tool after the map. To be accurate, altimeters must be calibrated daily at a location with a known elevation such as a summit or benchmark. Glacier surfaces are not reliable since their altitudes change. With a calibrated altimeter, you can follow a contour just like a physiographic handrail.

To navigate whiteouts you should also have a non-digital compass, such as the Silva Ranger, with a pre-settable declination (the difference between true and magnetic north). Whiteouts require two compass techniques: 1) Taking a bearing from the map to apply to the terrain, and 2) Taking a bearing on the land before the weather closes in. Although compasses don’t lie, they are tricky, so find a mentor to learn about aiming off, handrails, attack points, and the contour tangent method.

GPS units seem like the panacea for whiteouts. They identify your location with a single button push and can make whiteouts on featureless landscapes such as flat glaciers tolerable. Unless you’re a GPS buff, get a light and simple unit, such as the Garmin Foretrex 101. Combined with a UTM Grid Reader, or National Geographic Topo!, you can use the GPS to enter and follow way-points.

However, GPS devices still have critical drawbacks. For example, batteries are limited in cold weather since the chemical reactions that produce the current are slower. While Alkaline batteries are next to dead below 0-degrees F, the chemistry in lithium batteries works far below negative 40-degrees F. Keep the GPS warm by hanging it around your neck, inside a couple layers. Further save batteries by navigating with a compass and only use the GPS to spot-check your location every half hour or so.

The other drawback of GPS is they teach you nothing about mountain travel. Using simple tools – observing the mountains, your map, altimeter, and compass – hones your mountain observational skills and ability to navigate in whiteouts. Unless you’re into GPS as sport, the unit should stay buried in your rucksack 99-percent of the time.

Serious whiteouts – when the snow three-inches from your ski tips is inseparable from the sky – can make you nauseous and staggering like a drunk with vertigo. Yellow lenses help with depth perception. Some people toss a tennis ball streaming with surveyor's flagging to help see the snow surface or hazards. Another trick is fly-casting: tie one end of an 18-foot piece of 7-mm Perlon cordelette to your ski pole and cast the line onto the snow surface for depth perception. Since walking in a straight line is about impossible in whiteouts, have the second team member be the navigator so they can align the leader with their compass or GPS arrow. Then the navigator can yell “Right! More right!” as the team leader swerves from vertigo.

Practice is the only way to get better at navigating whiteouts. Venture into horrendous weather, flail away, learn, observe, but remember to stop if you’re unable to manage the hazards. You’ll discover navigation tricks of your own and Goodwill will appreciate the GPS donation.

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