I have two boats and am looking for a chart plotter for the second boat. I am considering buying a netbook with a 10" screen and running freeware using downloaded charts. I have a bluetooth GPS receiver that I currently use with my 17" notebook. Including the cost of the GPS receiver, it looks like I can have a 10" plotter for $315 or so. The boat has an enclosed wheel house so weather will not be a problem. I would run the netbook via a 12V plug in the wheelhouse.