Crankbait Running-Depths: The Apps Are Wrong--Sometimes
Since I divide my walleye fishing almost perfectly into thirds: 1/3 of the time jigging; 1/3 of the time rigging and 1/3 of the time cranking, my skills are challenged and I have to make myself “passable” at all three approaches. Way back when I was learning how to fish crankbaits it became obvious to me that dialing in running-depths of various plugs was paramount to the approach. If you can’t select a lure to run at the depth you choose, you have no way to consistently fish steep contours in Western reservoirs or stay just above weeds on flats, let alone pinpoint suspended fish out in the Great Lakes (or occasionally elsewhere).
Nowadays, anglers who spend much time fishing with crankbaits also spend time scouring the crankbait running-depth apps for data that will help them dial in their plugs. This is a good start and I highly recommend that you use the apps or find the older books with crankbait running-depth charts. Unlike the lure manufacturer's often guesstimated running depths, the best apps and books build their running-depth charts from actual experiments to document exactly how deep lures run. It’s the best data we have at our disposal to know precisely how deep any given crankbait runs. I got my first crankbait running-depth book in 1987 when Mike McClelland published his seminal study, Crankbaits: A Guide to Casting and Trolling Depths of 200 Popular Lures…that’s Mike McClelland the walleye pro, not Mike McClelland the bass pro…In 1991 I added the Holt and Irwin book, Crankbaits In Depth to my collection. That book charted “Dive Curves for Popular Crankbaits, Dive Planers and Leadcore Trolling”. Then in 2001 I added the 6th edition of Precision Trolling: The Troller's Bible by Holt, Romanack and Irwin. Between the info in the books and my own days-upon-months-upon-years of experimentation I made myself a bit of an armchair expert on crankbait running-depths. In that time I found some anomalies where the scientific dive charts just didn’t match my experience on the water. Let me explain…
I Love My Crankbait Running Depth Books! Not Pictured is My Copy of Precision Trolling Because Many of the Pages Are Stuck Together...Write Your Own Joke Here!
I was dialing in a bite using Bomber 24A’s out on the Columbia River when I found that when I switched from a clear lure with a metallic prism in the center to a chromed lure I just couldn’t scratch bottom in the same depths. The chromed lure (fully chrome plated including the lip) just didn’t achieve the depth I needed. I was using an aggressive “rolling rocks” approach of literally rototilling the bottom at high trolling speeds and I couldn’t even tick bottom with the chromed lures. I shook one of the chrome lures to see if I could free up stuck rattle BB’s inside and holy crap! That 24A Bomber had the loudest and most high-pitched rattles I’d ever heard in a 24A—and I had used them a bunch previously, but not that chromed finish.
Bomber Running-Depths Page in Mike McClelland's 1987 Book, All Depths Based on 120 Feet of Line to the Lure.
So I pulled out some Storm Deep Thundersticks in both clear-sided and chromed finish and noticed the same difference with rattle tone and running depth. What the heck was going on? This was back in 1991 and I had met John Storm, then president of Storm Lures a few times…enough that I felt comfortable calling him on the phone (yes, back then phones were actually used to talk to someone). I explained my findings with the shallower running-depths and louder rattles on the chromed lures and Storm confirmed, “You’re observant, Ron. Those baits are made of different types of plastic. Metal plating adheres best to ABS plastic. We’ve had our best success molding clear-sided and clear-lipped lures using Butyrate. The different materials have subtly different characteristics.”
Aha! Though my experiences didn’t match the science in the dive-curve books, there was still a logical explanation. Just because a lure is made by the same company and comes from the same mold, there are differences that were never addressed by the dive-curve experts. And here we are nearly 30 years later and I still have never seen a dive-curve app that distinguishes between different types of plastic from one color/finish to another. But if you are fishing tricky contours or trying to skim just over the tops of weeds or bottom slime it’s in your best interest to know that there is a difference!
OK, so the dive-curve studies of molded lures are going to have data based on either ABS lures or Butyrate lures (and perhaps other plastics too), but which is it? As consumers of that data, we may never know which plastic was tested. So we may not get the same results from our own lures not because we messed up any of the equation, but because we chose a different color lure, thus different plastic construction than the lure tested for the app/book.
Let’s take this another step. Not all lures have the same “guts” inside, even though they come from the same mold AND even if they are molded from the same plastic. For example, those lures with clear sides and a metallic prism inside don’t act exactly the same as other lures without the prism inside. They weigh slightly differently and thus run slightly differently. By the same token, lures with loose BB’s rattling in the body cavity are generally made without the body BB’s when they have clear sides or a prism insert inside. Again according to John Storm, "The BB’s would beat up the prism and scuff the internal plastic making it cloudy," so companies typically delete the loose body rattles if the lure has clear sides or shiny prism inside. When you remove the loose BB’s you change the weight and running characteristics of the lure…so it doesn’t run precisely the same depth as identical lures with body BB’s for rattles. Note that most lures with loose body BB’s also have a “thumper” chamber in the head…with a heavy BB, ball bearing or lead pellet that stays inside that chamber creating a rhythmic thump.
So for a Bomber or Storm lure—two companies that historically offered both clear-sided/clear-lipped Butyrate lures as well as metal plated ABS lures you could have several different lures all packaged with the same name:
Metal plated ABS lure without prism insert
Clear-sided Butyrate lure with prism insert
Clear-lipped Butyrate lure without prism insert
Various rattle configurations...body rattles? Chamber rattles? Varies by application and manufacturer. I have cranks with as many as 4 rattle chambers AND loose body rattles...talk about loud! Manufacturers often mix types and sizes of rattles to get multiple tones from their baits as well. Rattle chamber is visible in the head end of the prism lure below and in many clear-sided crankbaits (chamber is visible just below the eye on the middle lure. The other lures also have the rattle chamber, it just isn't visible).
Three Supposedly Identical Lures...But They Don't Run the Same!
Top Lure is Metal-Plated ABS Plastic, Middle Lure is Clear Butyrate w/Prism Insert, Bottom Lure is Clear Butyrate w/No Prism. Which Version Is In Your Dive Charts?
So for each lure, which version was tested for the dive-curve apps? In most cases we have no way to know…So we have no way to be absolutely precise on running depths. There-in lies the reason crankbait experts still exist…because you can’t simply use the app and call it good. You need to do a bit of experimenting to become somewhat of an expert on your own favorite lures. You have to dial it in. The apps and books will get you close, but to really “own the world” you’ll need to spend some time on the water!
Forgive me for continuing this discussion, but you need to know. There are external differences in various plugs that are not factored into the dive-curve apps. Take a look at your boxes of Flicker Shads. When this “new” lure came out it took awhile for the testing to get done for the apps. So I had to test for myself…and I found something curious. My most successful size 7 Flicker Shad for one Missouri River reservoir was running over a foot deeper than the same size 7 Flicker Shad in another color that I was doing the best with on a different Missouri reservoir. This time I wasn’t perplexed like I had been decades earlier. I started looking for differences. The deeper running lure happens to have smooth sides, while the shallower runner has cross-hatching scale patterns molded into the outside of the lure. The smooth version runs deeper than the rough-sided version. Seriously, if you haven’t noticed this, go grab your boxes of Flicker Shads. See…some have molded scale patterns on the outside of the lure and some are smooth as sculpin skin. They don’t run the same! Both versions catch fish, and lots of ‘em, but the minimal true testing I’ve done shows the smooth ones run deeper than the cross-hatched ones. And what about the difference when they changed from those in-bend light wire trebles to the current treble hooks? Did that change the running-depth? And aside from running-depth, do the fish prefer the vibrations of the rough-sided lures over the smooth ones? Which one gets bit more? I will confirm that at night, I seem to get bit more on the rough-sided baits…perhaps they are easier to “feel” in the dark?
Popular Flicker Shad Lures Come in Smooth Side (lower) and Cross-Hatched Finish (upper). They Don't Run The Same! (And no, most of us aren't fans of those in-bend trebles that came on the Flicker Shad for a few years. You can see that I had to rebend the front hook on the bottom lure--that means it caught fish!)
Lots of lure manufacturers offer different versions of their lures. For example the Bomber 15A has been manufactured in no less than 4 different versions since the first Pro Autograph Series baits came out in the '90's. Currently, the 15A is made in the standard model and the suspending model. The suspender has extra weights inside a mid-body rattle chamber. The suspender also has contoured eye sockets and gill plates while the standard model has a smooth head with just a small bump for each eye. These two baits not only run different but they are made in entirely different molds. The more “Pro” models, and “Suspending” models and “Silent” models a company puts out, the more we won’t have access to perfect dive-curves--though the apps do a pretty impressive job of trying to keep up with all the versions of popular lures. I happen to use lots of those specialized lures and I have to stay aware that sometimes the dive-curve is only known by me from my personal experience. But hey, that’s the whole point…getting out there and experiencing our fishing is the name of the game! Of course, and I stress YOU NEED THE CRANKBAIT RUNNING-DEPTH APP(S) OR BOOK(S), but that awesome information doesn’t mean we all get to turn off our brains when we fish. The scientific data makes our task of dialing in a crankbait bite much easier than ever before, but we still have to participate!
Addendum: Just found this paragraph on the back of a Bill Norman "N" series crankabait package referencing the different sound qualities of Butyrate plastic, "For more than 30 years, Norman Lures have been made out of butyrate. It's an old school material that requires more time-consuming methods of production. But while other plastic lures produce a high-pitched sound, butyrate creates a unique, softer thump. You can hear the difference--more importantly, so can the fish."
Addendum 2: Most of my favorite Bomber lures are now made of polycarbonate...so our old lures may run slightly different than the same lures fresh from the factory. So a Bomber 24A (awesome lure by the way) may be made of butyrate, polycarbonate or ABS (depending on production date as well as color) AND may have differing internal rattles depending on if it has clear sides or not. PLUS they respond and dive differently depending on how much current you are bucking. I've had chromed 24A's--presumably made of ABS--that would barely scratch 12 feet bucking current out on the Columbia. Yet I've had butyrate 24A's run as deep as 22 feet using the current to help them dig deeper rather than "float" them up higher like the ABS models. The last tournament I ever fished was on Oahe Reservoir for the long defunct In-Fisherman Professional Walleye Trail event. Used 24A's to "seine" the 16-17 foot contour and won $5000ish dragging contours. Just so you know, each lure used in the tournament was pre-tuned, pre-fished and proven. What I did was dial in each lure before the tournament and once a particular lure caught 3 fish I moved it to a box just for the tournament...then dialed in another. By tournament time I had 17 lures that I knew I could trust completely--each with at least 3 walleyes on its catch record. I let my daily amateur-draw partner pick whichever two they felt a hunch about, out of perhaps 6 or 8 different colors that had produced in prefishing. And I still have that box of proven 24A's just in case I need 'em at Oahe ever again!