When trolling for salmon the bridge can be a wee bit quiet. Not much to do, why not explore the features of the Furuno navigation system?
A very cool feature! It appears you can color code the track based on several different variables, the most interesting being depth. On the track screen you can choose color by depth, and then select the rainbow bar to set the range of depth to be associated with each color.
Setting the range of depths we wanted to troll allowed me to slowly map the bottom in the trolling area. The charts are often lacking in detail, they are designed to allow safe navigation, not to show where you will rip off a down-rigger ball. After a few passes all I had to do is keep the boat on the violet and aqua area to provide just the right depth for trolling, dark blue was a bit too shallow, green was too deep. I did not find a way to select the color order, but there is really no need.