I have a Garmin 48 (About $200). A unit to consider if you want, or need, a U.S. navigation aids database built-in, so you can navigate directly to buoys without entering co-ordinates. It interfaces with PCs so you can pre-plan routes, etc., and has a 12V power cord option, but battery life is quite good. Otherwise any smaller model is fine if you just need lat/long position. information.