What Map Datum Do I Use?

What is the best Map Datum to use with your GPS receiver?

I was questioned about this recently in a GPS class.  What is the best datum?

It just depends on what the hiker is going to do.  If one is going to plot coordinates on a map then the datum (in the  USA) to use is NAD27 CONUS (Continental United Sates.)  This matches the map best.

Receivers come from the factory set to WGS 84.  WGS 84 isn't the best datum to use with older maps.  That said, mapping software (Terrain Navigator PRO) and www.caltopo can shift to WGS 84.  Day hikers can feel comfortable using WGS 84 anytime.  Cell phones use WGS 84 too.

For more information about map datum go here.