Very simple and intuitive interface. It works just as I had hoped. However, there are two points that seem to be glossed over at times. First, this unit has to be connected to a 12 volt power supply such as a car battery or one of those car battery booster type units. So if you plan to use it in a kayak you need to plan for a power source. Second, the screen/keyboard unit is not water resistant at all. If there is a chance of rain or spray you need a ziplock bag or some such to cover the thing.