On Mon, 06 Mar 2006 05:01:05 GMT, otnmbrd
wrote:

Gee, I wonder how I navigated all over the world, offshore, prior to GPS,
if I had no viable alternative to GPS.

Probably celestial and DR unless you were lucky enough to be on a ship
with a good inertial system.

Tell us about the times when you couldn't get a celestial fix because
of clouds.