How would a southern hemisphere compass differ from a northern hemisphere compass?

The Southern Hemisphere compass will naturally align it self with the South Poleanswer 2 A compass designed to work in the Southern Hemisphere will have the needle/card balanced differently, for in the S hemisphere the S pole will cause the compass to dip slightly - and opposite to the northern hemisphere.The compass manufacturers divide the Earth into five zones for balance. Some folk need a compass that is insensitive to this effect, (e.g. Army) and for this they choose to have the needle a smaller part of the weight balanced on the pivot, and have a liquid filled compass.Regarding the first sentence above, the compass needle actually aligns itself with the lines of magnetic force at your location - which will still result in a N - S alignment.