GPS Geo-caching

[Paul]

I am used to geo-caching with a map and compass but have found that either I'm getting older and dafter or North is "dancing" round a bit.

I recently got an E-Trex GPS but setting the North on the GPS as Magnetic North, there is something like a 5 degree difference between the GPS and my trusty old Silva.

I read somewhere that the poles are shifting rapidly but I thought that the GPS system took that into account so anyone got an idea about what's going on?

I ask because I may need to find my Geo-cache at night it might be nice to use the GPS and walk to a waypoint.

Problem is I'm thinking that any waypoint set on the GPS will gradually "drift" if magnetic north keeps up it's little dance and GPS's can't cope.

Thanks.

[Skean Dhude]

Strange as GPS is a point on the earth. The sats should still be in the same place, the signals should be the same so although true north may change that shouldn't in theory make any difference to GPS. It isn't linked.

Best to set up some tests with your e-Trex and check in a year or so.