I am using a Dell Laptop with Maptech Software (Offshore Navigator) Connected to a Garmin handhel GPS using Garmin''s serial connection. This is very simple to set up ( I am not overly computer literate, if I can do it anyone can). You must use Garmin''s own connector a few wires to solder. Interfaces with the computer and lets you know your exact location on the chart. I use it with the computer battery ( I carry a back up fully charged), I recharge off the AC when I am shore sied connected to AC. I also have a DC adapter that I can run the computer off of through cigarette lighter plug. I basically use my laptop when navigating a port that I am not familiar with and to plot courses to waypoints.
Hope this helps. If you need any more info e-mail me privately