Choosing a compass
Choose your compass with care. The most appropriate type for use in
scouting is probably the orienteering compass. A good one will have a well
balanced steel magnetic needle that settles into position quickly. The
needle should be coloured differently at each end, usually red at the
north end. If the tip glows in the dark then even better.
The base plate and dial are usually strong plastic. The dial will have
increments of around 2° marked clearly. On the dial itself will be faint
meridian lines (faint parallel blue lines pointing in the same direction
as north on the dial). Some even have extra information such as magnetic
variation or declination degrees marked on the dial. The dial also has an
arrow marked on the bottom aligned with north on the dial.
The base plate should be transparent and have scales in both metric (cm
and mm) and imperial (inches). A magnifying glass, clinometer, sighting
mirror and adjustable declination screw are all welcome extras.
Don't forget a strong strap attached to the base plate which should be
securely held at the other end to your shirt pocket buttonhole or around
Why is it spinning like that?
Because a compass is based upon a magnet the needle can be affected by
magnetic fields and materials such as iron. For instance your belt buckle,
a zip, caribiner. Even mineral deposits in the ground can offset your
compass. Don't just look down either. Look around and above you. Sitting
under a power line or near an electric motor will not do you any favours.