Keeping paper charts as a backup is a must. Electronic devices
can and will fail. Raster charts are just scanned paper charts so the
accuracy is pretty much identical. Keeping them both updated is
a chore. Vector charts (like CMAP) are digitized from those same
paper charts so the accuracy is also affected by the digitization
process. Our CMAP charts showed us going over land a few times
on the ICW and especially in the Bahamas. All in all, the convenience
of the electronic chart at the helm was very valuable. We would have
run aground quite a bit more often if we were using paper charts simply
because the immedeate feedback of having an electronic chart right in
front of us when at the helm is hard to beat. In our case the device is
a NAVMAN 5500.

Doug
s/v Callista

"David Ditch" wrote in message
...
Is a GPS map like the Garmin 176C a good alternative to carrying NOAA
maps?
I live in the Chesapeake and would like to not have to carry large maps
around with me.

Worth the expense if I have the money?

David