Well, I ruled out the ifinder (not waterproof). The courser resolution on
the Magellan Meridian Atlantis is actually easier to read than the Garman
Map76, due to the lines being bolder.
Now, I've found a dash mounted unit by Hummingbird, the Matrix series which
(#17 & 20 haave a 5-1/4" diag. screen) combines a depth sounder with the
gps, using either their own receiver or yours.
Anyone have any knowledge on the performance/accuracy ot this unit?
thanks,
LD