Hey Jim:
The Garmin Map76 has a base map with streets and highways and it's a great unit for fishing. The base map also has a rough outline of bigger lakes but if you want detailed maps of the lakes you fish you'll need to purchase and upload them.
There are several types of mounts available for the Map76 so you can have a mount in your vehicle and one in your boat. There's even one for a motorcylcle or bicycle handlebar, which also works on round boat railings.
They are a little bulky to carry in your pocket but would fit easily in a fanny pack or back pack for hiking or hunting.