A snap weight is a heavy sinker that is attached to the line with a pincher-like clip. It can be placed at any point of the line. A snap weight makes the line’s physics and forces and the resulting curve geometry much more complex, but because Trolling Angles measures the actual resulting line curve, it’s easy for it to determine the lure’s depth regardless of the size of the weight or where on the line it is positioned.
The Process
- As always, enter the rod tip height.
- Start to measure multiple initial angles exactly as you would without a snap weight.
- When the desired amount of lower line has been deployed, take a length and angle measurement before attaching the weight.
- Attach the weight near the rod tip.
- Deploy enough additional line so that the weight is just below the surface.
- Take an extra line length and angle measurement at that point.
- Continue to deploy line and take measurements until the desired depth or total line length is reached.
That’s it. This straightforward and obvious process will result in an accurate depth curve.
Discussion
This graph shows the submerged line of 3 related configurations, with the same neutral buoyancy diving lure, a 2-ounce snap weight, each trolled at the same speed of 1.8 mph, each with a total line length of 100 feet. One has no snap weight, one has a snap weight at 20 feet, and the third has a snap weight at 50 feet.
At the point of the weight, the analysis will show “faults”, because the angles change differently than the fault detection algorithm expects. This is normal and can be ignored.
Lower Portion of the Line
Notice that in the line below the weight, each configuration follows the same curve shape, which is caused entirely by the lure. It keeps the same shape as it is lowered deeper into the water. Since this is a diving lure, this part of the curve shape does not change significantly with trolling speed. At greater line lengths, the line angle is shallower, so adding more line below the weight does not change the diving depth of the line as much.
Upper Portion of the Line
The snap weight transforms the line into a weighted configuration. The lower part of the line also places a drag and downforce vector on the upper portion. Although the angle of this vector does not change with speed, its magnitude changes significantly. The shape of the upper portion of the line changes dramatically depending on trolling speed and the size of the snap weight, but also on the size and shape of the lure and the drag and lift of the lower portion of the line.
Conclusion
Depending on the depth and speed you wish to troll, and the line length you prefer, it may be an advantage to place the snap weight at a different place, and to use heavier or lighter weights. Regardless of which configuration you use, the Trolling Angles app can determine a reliable depth curve.
