Bobbie, Two more things about the Raymarine Unit: 1) The Navionics electronic charts are available in different sizes/coverage areas. I purchased the larger (XL3) format Navionics Gold #2G913XL3 (I paid about $180.00). It covers all waters of Puget Sound, Vancouver Island, and all waters on the mainland side of BC up well beyond Port Hardy. This would probably cover anywhere in the region you are likely to go with an M-boat. Go to the following site for a map of coverage: http://www.navionics.com/Charts2.asp?ContinentID=5&RegionID=19&ChartSizeID=6... lassic=0&Gold=1 Navionics Gold #US912XL3 covers all of Puget Sound all the way south to, and including, Baja California and the Sea of Cortez (but lacks BC waters support). http://www.navionics.com/Charts2.asp?ContinentID=5&RegionID=29&ChartSizeID=6... lassic=0&Gold=1 2) I should add that Navionics charts are nautical charts only--they do not offer land-based topographical or street maps at this time. Some Garmin units offer land-based mapping, though that is small consolation if you are on a Mac, and can't upload them! Best, Scott