It is a system that uses the GPS and controls the steering system on the boat to take the boat to a pre-determined location or to travel in a pattern. I will use mine to lock in a trolling pattern around a reef or bouy for instance. Once you program in a location (even Man Over Board) the boat will manuever around that position. I'll be able to program in a trolling pattern then either rig baits or fish while the electronics drive the boat. The Furuno system also senses wave action and will compensate the ride as best as possible.
I'm sure someone else can do a much better job of describing what an Autopilot system does. I haven't had mine in the water yet but I'll create a report after our maiden voyage.
