Ray,

Along these lines I would like to be able to use GE off line as a
navigation aid. Some of the areas I cruise in have fairly gross
differences between charted lat/long and GPS lat/long. It seems the
difficulty is getting past the GE cache limit, 2GB if I am correct.

So, what I would like to do is download a fairly large area and then
track my progress via GPS. Doing this in combination with my chart
plotter, radar, etc.

If you can solve THAT issue then I think you have something unique.
Maybe also illegal.

Or, if there is a already a way to do that, I would appreciate hearing
about it.

Many thanks,

Howard

Howard,
The 2GB cache will cover a lot more ground than most imagine,
especially in terms of boating distances. The key is to 'preview'
your trip while connected and not concentrate zoomed-in viewing
outside of areas you're likely to need.

An easy way to cache a route is to use the Path Tool in Google Earth
to rough out a track, highlight it in the places menu, then click the
'Play Tour' button at the bottom of the Places menu. This will cause
GE to 'fly' your route at low altitude. You can adjust your flying
speed in Tools - Options - Touring to pace it with your internet
connection speed to grab the imagery. You can get a similar effect
with more 'stand-off' range by creating a folder and filling it with
placemarks spaced along your route. GE will zoom out more while
flying between placemarks vs flying a route line.

If you're really into experimenting, then Google Earth Voyager will
let you 'scan' a defined area. GE Voyager is easy, but you've got to
follow the instructions pretty close (see http://destinsharks.com/google-earth-maps/162
for more information).

As far as offline charting with GE goes, EarthNC Plus Google Earth
charts are designed for this use case such that navaids, depths, etc..
are all available on your local hard drive. Real-time tracking is
available with GooPs GPS to Google Earth software, and a low-cost USB
GPS. The entire set-up, less laptop, is only $160 including a USB GPS
unit.

- Virgil