I have the Dualxgps150A and use it with the IPAD and IPHONE for Navigation, it works great. Many chart options for the IPAD that are very reasonably priced. For me this makes more sense than spending $100's for a marine Nave system for the lake if you already have an IPAD.
http://www.amazon.com/Dual-Electroni...=dual+xgps+150