"Larry W4CSC" wrote in message
...
What I can't figure out is why I haven't seen a CD software of the Defense
Department's underwater mapping system, making your $700 depth finder
unnecessary. The DoD has mapping data of ever underwater place on the
planet. This should be coupled with your favorite nav software so instead
of the stupid old chart's little depth numbers, you'd get an underwater
surface contour map in any direction around your boat's GPS
position....like the street maps ashore. Every known underwater
obstruction would be there that they know of.

Well, Nobeltec does do that. It produces a 3D countour map of your location.

Meindert