The Trolling Angles app allows you to measure and use the speed and direction of water currents, while trolling, using only your own fishing rig and your smartphone.
Current is Critical
Of all the different factors that determine the depth and performance of a trolled sinking fishing rig such as a lure with a sinker or a downrigger, trolling speed is the most variable, inscrutable, and critical. The readily available boat speed over ground (SOG) indicated by your GPS does not control the lure’s depth. Rather, the lure and line are controlled by the apparent speed of the rig with respect to the water or speed through water (STW).
In still, slack water, SOG equals STW. However, a huge percentage of trolling is done in moving water, such as large rivers, tidal currents, other ocean currents, and wind-driven currents on large water bodies.
If you don’t understand and account for water current speed and direction, you have no hope of understanding your lure’s depth, or optimizing your lure’s action, or trolling at the most effective lure speed for your targeted fish species.
An experienced deep-water troller knows how to estimate water current and its effect based on the observed angle of the downrigger line. The Trolling Angles app does essentially the same thing, but with accurate angle measurements and mathematical calculations.
Measure Current with Trolling Angles
The Trolling Angles app uniquely allows you to
- measure water current velocity (both speed and direction),
- account for water current, calculating the lure’s true “Speed Through Water” and actual depth while trolling.
It does so with only the app running on your smartphone and with the trolling rig you are using while you are fishing. No underwater probes. No government tide charts or current buoy data. No guessing.
Three Velocities
The velocity of the boat and rig over ground
equals the vector sum of
the velocity of the boat and rig with respect to water
and the velocity of the water current.How it Works
The basis of a Trolling Angles depth curve is a “Calibration”, which is simply a set of line angle measurements at different line lengths for a single speed. The app uses this data to calculate a depth curve, which includes the line angle at every point on the line.
If you collect a few different calibrations for the same rig at different speeds, the Trolling Angles app can reverse the process, and by knowing your present deployed line length and a single line angle measurement and line direction, the app will:
- interpolate between the known calibrations to determine your rig’s present apparent velocity through the water.
- compare to the GPS velocity to determine the water current velocity.
This does require some one-time effort to measure a set of Trolling Angles calibrations for your own rig at different speeds to use as a gauge. Once that is done, you can measure the water current at any place or time with only a single line angle measurement. Then, the app will use your GPS Speed Over Ground to show you the true apparent Speed Through Water, so that you can control your boat to the optimal speed.
Read trollingangles.com for much more information and download Trolling Angles from the Apple App Store or Google Play.
