I have a Garmin eTrex Summit Hc handheld and was thinking about buying the Inland Lakes Map Cd. Does anyone here have any experience with this unit and the lakes map. I only have a small 14 alum. boat that I fish out of and it already has 2 Hummingbird fish finders. One on transom and one on trolling motor and both work great just no GPS capability. Was thinking about using my had held for something more than marking structure. Any responses appreciated.....