Before using the app for trolling, a “calibration” for your trolling rig must be established. A calibration is a set of line lengths and angles that describe the geometry of the line profile of a particular rig as it is trolled at a particular speed.

First, prepare the fishing rod, reel, line, and other terminal tackle exactly as it will be used to troll.

A trolling reel with a line counter is preferred, but is not required.

Set the boat running in a straight line at the desired trolling speed over water deeper than the depths at which you intend to troll.

Reset the line counter of the reel so that it reads zero when the terminal tackle is at the rod tip.  Place and adjust the fishing rod and attached reel in a rod holder.  Release a length of line from the reel so that the terminal tackle is submerged somewhat below the surface and is running true.

Press the Start button to start a new Trolling Angles calibration.