On the Calibration screen, press the Add Measurement floating action button 
, to begin adding line angle measurements, or press the details chevron icon to the right of a particular measurement to modify the line angles for that line length. The Measurement panel will be displayed
Turn on the GPS switch in the middle of the screen to display the calibration’s Speed and the actual boat speed as a convenience so that a consistent speed may be achieved throughout calibration and trolling.
Recording the Line Length
The app will fill in the length field, using the Preferred Line Length setting. You may always enter a different length if you wish.
One measurement should be taken with the terminal tackle only slightly below the surface, but deep enough so that it is running true and undisturbed by the water surface. Other measurements should be taken with reasonably spaced different line lengths, perhaps 10 or 20 feet apart. The first measurements where the line angles are steepest and most variable are the most critical. Use smaller line length intervals for the shorter line lengths.
Before every measurement, check your line counter and release or recover the line or change the Line Length field to match the reel’s line counter to the Line Length field, and let the lure stabilize for a few seconds at its depth.
The Trolling Angles software accounts for the unsubmerged portion of the line above water, so always match the Line Length field to the value displayed by the reel’s line counter.
Without a Line Counter Reel
If you don’t use a line counting reel, a great option is to use a commercially available clip-on line counter that is not incorporated with the reel. Alternatively, you may determine the line length by another technique, such as counting reel handle revolutions, counting level-winder traversals, counting manual line pulls, counting line color changes, observing a pre-marked line, or others.
Preferred Line Length
The Measure Line Angles panel will automatically fill the Line Length field according to your Preferred Line Lengths, which is established in the app’s Settings section. This setting is a comma-separated increasing list of preferred line lengths with up to 1 decimal point precision. At each new measurement, the app will use the next preferred line length, or technically, the smallest preferred length which is greater than all lengths currently in the calibration.
Optionally end the list with a value preceded by a plus sign. The app will increment by this value when all preferred values are smaller than the largest length in the calibration.
If you are using a Preferred Line Lengths setting while using the Smartphone Angle Sensor or the Autocline, you do not need to enter any numbers while taking angle measurements. Just deploy the indicated length of line, take the measurement, and press the “Done (Check Mark) button.
Auto Advance
If the Auto Advance switch at the top of the screen is on, the app will automatically advance to the next greater preferred line length after a measurement is taken. If the switch is off, the Line Length is unchanged after a measurement, so that you can take additional measurements at the same line length.
You can use the double chevrons to advance to the next greater or lesser preferred line length.
Pay attention to the Auto Advance setting. By default, it will be set On when you start by Adding a new measurement, and to Off when you start by modifying measurements for an existing line length.
Measurement Details
The top or left section shows each of the angle measurements recorded for this same line length, along with their mean (average) and standard deviation. The mean is used as the angle shown on the main calibration screen which is used to calculate the depth curve.
Any of these detail measurements may be deactivated with the check mark or fully deleted with the trash icon so that it is not used. If an angle is wildly different than the mean of several other measurements, it is probably an inaccurate outlier, and may be inactivated or deleted.
