NavList:

As a land navigator, I can confirm what Murray wrote. Land-nav compasses are set up so you can adjust for magnetic declination, and triangulation requires knowledge of the local magnetic deviation from true north. In CN, declination refers to solar declination. If you are going to use a land-nav compass, be aware that many are set up for particular magnetic zones. For worldwide use, you need one that has a 'global' needle balanced for any zone, like the Suunto MC-2. None of these land compasses are truly gimballed. But I suppose if you were triangulating from coastal landmarks the Suunto might be useful.