Recently bought a Garmin 162 w/o antenna. I move it between my boat and my car. If you have a PC with a serial adapter, you can get a wide variety of software that let you do some really useful stuff - 3D mapping of the bottom, track across real (i.e., scanned) nav charts, etc., etc.

It's probably overkill for inland waters, but I'm just attracted to toys. However, I've tried a number of the better known brands as well as read other user's comments about this and other GPS units. They're all pretty good.

Enjoy, you won't regret it.

Take care

Michael