Laptops are great if you have the the room(some were dry and out of the sunlight)I also believe that you would need a inverter.
I have a Garmin 182 and have 1 chip that goes from Gauges dock at Saltspring Island all the way round the outside of the island back to Port Hardy.Has the tide tables,great zoom,charts show all contour lines.I find this a great GPS for a 17ft boat.For $100-$200 more you can have it in color.