Edited by Rachel Duncan 4th Edition ISBN 0-907649-91-2 London ...

62 RGS-IBG Polar Expeditions Manual
find that your feature is not on your map. Pencil it in and note its bearing. Do this
again after a few miles and by triangulation you can determine its location. Maybe
you could have it named after yourself.
6.8 The environment
Reports of temperatures in polar regions tend to emphasise intense cold. As a rule, most
polar journeys are undertaken during the late spring and early summer when the weather
can be quite balmy. However, it is prudent to study expedition reports to obtain a true
indication of the conditions that you will encounter. Be prepared for the worst and be
pleasantly surprised with the favourable.
Every task undertaken in the extreme cold will be far more difficult to complete
than in temperate or hot climates. To take out the map or set compass bearings while
wearing heavy gloves or mitts may be uncomfortable and awkward but, perhaps more
important than when in the warm, so never skimp on the number of readings you take.
In extreme cold, instruments will be difficult to manipulate. GPS or calculator
batteries may not work. Electronic and computer programs could be lost unless kept above
a certain temperature.
Most polar journeys involve prolonged periods of self-sufficiency and
commitment. There are few stores on the polar ice caps and not much chance of replacing
missing or lost equipment. Ensure that everything is robust and capable of withstanding the
conditions to which you will expose it.
6.9 Fog and whiteout
Fog is essentially cloud on the ground. Visibility will be restricted to your immediate
surroundings, 50m or less and features that had been relying on for direction will have
been obscured. If you are also on snow, the sensation will be that of walking in a "ping
pong" ball. Above, below and to your side will all look white. Ground features such as
tracks, crevasses, dips and mounds will all merge into one.
If travelling in whiteout or fog you may have to regularly stop and take compass
bearings perhaps every few minutes. Once you are well practised, you may be confident to
walk all day with just glances at your compass. Knowing your rate of travel will help you
assess your distance travelled. The strength and direction of the wind, temperature and
conditions underfoot could well influence your direction and speed. A crosswind may
make you crab sideways, a headwind will slow you down.
With diligent use of the compass, it should not be necessary to have a partner
behind you to give corrections to your track.
If you are off bearing by a few degrees there will still not be a great percentage
error by the end of the day. An estimated position can still be plotted and with
improvement in visibility, corrections can be made. Navigators at sea may travel hundreds
of miles in fog and, on a clearing or sight of the sun or stars, very soon assess their true
position provided an accurate log has been kept during the fog period. You may need to
stop and await better visibility if you are requiring pinpoint accuracy or you are in the
vicinity of hazards, a cache or a specific landfall. Obviously, with a GPS you can monitor
distance travelled and check your location regardless of the weather.