By Mark Romanack
The Precision Trolling Data phone app is the most comprehensive source for lure depth ever created. The PTD app is created by trolling lures and other trolling hardware past a scuba diver who documents the diving depth at various lead lengths. The question is does trolling speed influence diving depth and the answer is yes and no depending on what device is being tested. Lures and devices that sink are very speed dependent. Meanwhile, lures and devices that float at rest and dive when trolled are not speed dependent and achieve the same depths at a host of different trolling speeds.
The most common question we get at Precision Trolling Data is why is there no trolling speed indicated on many of the lures featured in the app? In the Precision Trolling Data app a number of different lures and trolling devices are featured. The items that are speed dependent in regards to depth do feature one or more trolling speeds, but items that are not speed dependent feature no trolling speed indication.
In general, speed dependent lures and devices are things that sink including diving planers, Snap Weights, Tadpole Divers, Lead Core line, etc. The slower these devices are trolled, the deeper they run. In the same token, the faster these devices are trolled, the higher in the water column they run. So in the case of sinking devices, trolling speed is critically important to controlling the ultimate depth these devices achieve.
In the case of many of these speed dependent items, the PTD app provides several different trolling speed options to provide anglers with as much information as possible.
Floating lures and devices however are different. Anything that floats at rest and dives when pulled falls into a different category. This category includes most crankbaits and floating divers such as the Jet Diver. Floating lures and devices are not speed dependent or in other words they achieve the same diving depth regardless of the trolling speed.
Here is why floating lures and devices are not speed dependent. When trolling speed is increased, the lure or device is digging harder and trying to achieve more depth. However, at the same time the amount of friction or upward force applied to the fishing line is increased as speed is increased. This sets up a situation where the two competing forces essentially cancel each other out and the end result is that diving depth is not influenced measurably by trolling speed with floating lures and devices.
All of this information was part of the initial research Precision Trolling conducted more than two decades ago, prior to publishing their first depth guides. Trollers may also find it interesting to note that most fishing lines are very buoyant and this also contributes to floating lures and devices not being speed dependent. Even fluorocarbon line which is marketed as a sinking line, actually is neutrally buoyant and does not influence the diving depth of lures or devices trolled using fluorocarbon line.
WHY SPEED IS IMPORTANT
While trolling speed may not influence the diving depth of popular floating crankbaits, trolling speed is important in terms of triggering strikes. Faster trolling speeds cause lures to have a more aggressive action, while slower speeds deliver a more subtle action.
In general, successful trollers try to troll as fast as they can go and still be rewarded with strikes. This strategy works to cover as much water as possible, while not limiting the number of bites.
Unfortunately, there is no app or guide book that tells how fast an angler should be trolling to be successful. Therefore, the best approach is to use common sense and to vary trolling speeds periodically in an effort to see if faster or slower speeds are most effective on any given day.