Using my Nuvi 650 to navigate to favorite fishing spots

I haven't tried it myself but you should be able to do just that by either looking up the location on Mapsource then transferring it to the 650, or going there one time and marking the waypoint. The problem is that if you are too isolated from the standard road map, it may be difficult to navigate to the spot. However, you can buy the topo maps and see the forest roads or trails leading to it, but you still couldn't navigate to it in the same manner you do to a street address.

Well, if they are your own fishing spots, then you would have already been there. If that is the case, then you can hit the car when you get there and save the location to your favorites (don't hit your car, then one on the screen). Then when at home open the gpx file in POIEdit and save as a csv file. Then import that into the unit as a custom POI.