Lin Pardey somewhere on their site told of what happened to them when they
tried such.

http://landlpardey.com/

net net, the compass was off by a considerable margin. She explains why.

Anybody have any experience using a Northern Hemisphere compass as far south
as say New Zealand? I *know* you're supposed to have a s. hemisphere
compass in an ideal world, but I'm wondering how much the card deflects i.e.
is it still useable, even if tilted.