So here's a random thing that I learnt yesterday. Compasses are region-specific and the needle will "stick" if a normal compass is used in the wrong region! Australia and New Zealand are in magnetic zone 5. If you want a #compass that works anywhere in the world, it needs to have a "global needle", which is built a bit differently to account for the problem of the magnet aiming directly through the earth to magnetic north and dragging the needle down with it.
@Genesis yeah, I have a North American compass that I often bring in my pack in NZ, though I've not actually used it....