Constructing a route ... From Greg in another forum ...

You have to tell the unit what waypoints to use in your route. You can make a route two ways as the manual says. Go under the Nav menu tab and select the Waypoints, Routes, Tracks menu and use the right arrow key to open the menu. Use the Up arrow key to get to the Options menu and open it. Select New then New Route and name the route. When done with that you will go to the Plan Route menu and start selecting waypoints. Don’t forget to save it when you are done. The way to make a route ‘on the fly’ is to move the cursor when on the Chart View, to a location or a waypoint you already have marked and then use the GOTO button. Select additional waypoints until you have your route constructed, then go to the Xpress menu on the Chart View and select Save Current Route.

You can also make a route in the HumminbirdPC program.