Larry,

All sage advice however I do believe these things are very much like printers.....the ink cost's as much as a new one. Personally I buy one at Costco every year, in the low 100 dollar range, then give it away the next. You always have a current chart (map) and don't have to go through the drill of updating a device that is probably already out dated. Option two, a bit more costly is a Garmin 496. This is an airplane model that works in the sky, on the roads and if you like, on (not in) the water. Best part about the 496 is the XM weather which updates every 4 minutes, for a bus, it's like having a very good color radar that spits out cloud tops, all that stuff. See some purple on I-70 while you are on I-70 and its 50 miles ahead...perhaps a wise idea to stop. XM wants a fee but its worth every penny.............. Air Gizmo's makes a panel mount so that you don't have a carbunkle on your dash. Just my opinions