Line out vs rod tip height info.......
HI GUYS, The topic of line out and using formulas to calculate lure running depth are commonly asked of us at Precision Angling Specialists, LLC. Were the guys who produce Precision Trolling, Precision Casting and Precision Trolling Big Water Edition. Collectively weve spent over 12 years researching crankbaits and other trolling gear using scuba techniques to confirm depth. Lets talk about lead length or "feet back" first. When we refer to "feet back" in our books we are referring to the actual length of line let out between the lure and the rod tip. We measure this by zeroing out the line counter reel with the lure reeled tightly against the rod tip. Its also important to note that the "feet back" measurements in our books are actual feet. We calibrate our reels before testing, by measuring out 100 feet in an open space and then comparing our line counter reels to actual measured distances of 100 feet. If the reel overestimates the distance we take line off the reel until it calibrates at 100 feet. If the reel underestimates the distance, more line must be put on the reel to calibrate at 100 feet. The good news is most quality line counter reels will calibrate or come close if the spool is filled to capacity. To get the best accuracy I recommend that you use the same brand and model of line counter reel and also that you load all your reels with the same line type and diameter. Okay, now lets look at the rod position in relationship to the water. We test with the rod at the water surface, not two feet above the surface. If you use in-line planer boards, the board becomes the zero point. If youre flat line trolling we recommend positioning the rod tips at or near the surface. If you use dual board skis with a mast, the further above the water the fishing line attaches to the tether line, the more shallow the lure will run. The ratio is not 1:1, in other words if you raise the rod tip one foot it wont shave off one foot of depth, but it will cause the lure to run a margin less than our posted depths on the Dive Curve charts. Compensate for this by letting a little more line out if you feel you must, but remember that its better to position your lures above fish, not at their level or below them. Lastly, we need to discuss the concept of using mathematical formulas to predict crankbait running depth. If only it were that simple. As Jim Stedke pointed out, calculating the running depth of a crankbait by measuring lead length and line angle does not take into consideration that the line out to the lure is not actually running in a direct course from rod tip to lure. Most of the line is actually floating on the surface. A bow or curve is formed in the line as well because of the forward motion of the boat, making it all but impossible to calculate the exact running depth of the lure using a formula. The problem is that speed changes the curve in the line, line types change the curve and so do water currents in the water. All of these variables can not be controlled to perform the necessary testing, so in essence using math formulas amounts to guessing. Precision Angling prefers to go under water and actually measure the lead lengths and depths the way we have done for 12 years. Its time consuming and difficult work, but the accuracy we produce in our Dive Curve charts can not be matched with formulas and calculations. Sorry. If it were that simple we would have done it years ago. Thanks guys for reading this especially long response. Good luck trolling and thanks for using the Precision Trolling information. Best fishes, Mark Romanack
