Topo USA 2.0 DVD Comparison of Garmin USA Topo map CD with Delorme Topo USA 2.0 CD The Garmin maps are derived from the 1:100,000 USGS topo maps. Additional Comparisons to the USGS DRG topo Maps -Including Track and Waypoint Data Garmin USA Topo CD With Depth Contours - Wassau Sound, Savannah, GA