Kokanee Dodger Tech Report by Bill Herzog
Waves, frequency, vacuums, thresholds...whew...we’ll be taking a page from the book of hydrodynamics to help choose the correct dodger, check out some out of the box dodger combos plus look at some exciting new colors/finishes.
We love to troll for kokanee because, quite frankly, they can be much easier to catch than their larger anadromous cousins, salmon and steelhead.
When the bite is truly en fuego, we can engage in one of my favorite activities—“tackle box challenge”—to see just what the little tasty chrome buggers won’t strike.
However, all serious kokanee trollers know most of the time enticing bites can be a bit of work and matching the right size, color, finish, and design of dodger ups the ante way in our favor. Especially when angling pressure is high, weather and lighting dramatically changes, plus picking and staying with ideal trolling speeds can be the difference between a quick limit and just trolling practice.
Choosing the correct dodger is much more than just what happens to look good.
To help choose the right dodger for current conditions, we must look at how each style and size of dodger works when pulled through water (speed). While we each have a favorite style and color that is our “go-to,” you know the one that we always fall back on (I’m as guilty of this as anyone), knowing how each style performs helps eliminate personal voodoos and helps leaps when dealing with difficult landlocked salmon.
To begin this process, we have to look closely at hydrodynamics, the science that deals with water motion. When we at Pen Tac went to Boeing airplane wing engineers to make the most effective, responsive, versatile, highest action steelhead and salmon spoon on the planet—the BC Steel—hydrodynamics was the key.
Starting with waves, in this case each bend in the dodger is considered one wave.
Two factors determine the degree of motion- frequency and amplitude.
- Amplitude is the power of the wave.
- Frequency determines how often the wave occurs.
Let’s use beach waves as examples.
A one-foot wave has low power, whereas a five-footer has greater power, or amplitude. If a wave hits shore every twenty seconds, this is a low frequency compared to one that hits every five seconds.
A trolling dodger is a wave formed in metal. When moved (trolled) through water, it reacts like any other wave, with frequency and amplitude.
Let’s look at two common styles of dodgers to compare frequency and amplitude; the rectangle 4/0 (like a Sep’s, Gold Star or Luhr Jensen) and the teardrop (like a Shasta Sling Blade or Rocky Mountain Tackle). Turn them sideways and compare.
The 4/0 Seps has a more pronounced wave (bend) than the Sling Blade. It has more power; a larger wave. Although amplitude can be easily predicted by just looking at the wave like this, frequency will be determined by how fast it is pulled through the water.
Action will also be determined by overall design.
Stay with me, kids. It will all make sense soon.
Closer examination of the two dodgers reveals there are two waves in each design.
The top wave is smaller than the bottom wave, both are important as the action of the dodger is determined by the interaction of these two waves. Here is where frequency and amplitude come into play.
Let's say both are trolled at 1.2 mph.
Water is passing on both sides of the dodgers at equal rates. Both will swing out, then straighten. What is going on, anyway?
Water pressure on both sides of the dodgers are not equal.
Water runs along one side of the dodger, but due to the first wave on the head, water flow is somewhat blocked. As a result, a vacuum is being created in the concave area of the dodger due to near-zero water pressure and water flowing parallel to concave areas are creating suction. This vacuum and suction is what causes both dodgers to swing one way.
Because the dodger is being pulled through water, the concave side (lower lip) is broadside to the current and will be pushed back to a straight position. Of course, once it goes back, another vacuum is formed on the bottom hump on the base and back out it swings.
We anglers call this “action”.
If we create a larger wave, like the 4/0 Seps compared to the slight wave of the Sling Blade, there is a larger vacuum, greater pressure, more suction and greater movement of the dodger. Having two waves, the bottom wave will pull left, but when pressure is equalized and swings back straight, the top wave will give slight pull to the right.
Now let’s put it all together. Each style of dodger has a speed threshold. This is where 90% of all kokanee anglers get lost in dodger choice. These dynamics only work within a given speed range for each style.
Dodger action is regulated by amplitude of the wave, the bend in the metal.
A 4/0 Seps has two strong, pronounced waves, needed when you want to impart maximum action at slow speeds.
They are relatively close together, creating quicker frequency. Again, closer waves are important for action at slow speeds. If you troll a dual, pronounced close together wave dodger like a 4/0 Seps faster than 1.6 mph, it will abort its action and spin in a circle.
On the other hand, a weak waved dodger like a Sling Blade, featuring a very slight wave on the head and a weak wave at the base are needed when trolling at higher speeds. The waves are farther apart, with longer frequencies.
Because of this, we can troll a Sling Blade style dodger up to 2.5 mph without it reaching its speed threshold and begin to spin. But, troll a Sling Blade at .09 to 1.2 and this longer, less waved dodger barely swings with a slow and slight movement. Remember for both styles, there is a minimum trolling speed.
At too low a speed, amplitude is diminished and proper action is lost.
Finally, consider dodger width.
A wider blade has greater surface area, featuring more vacuum and pressure than a narrower blade. A simple rule of thumb can be applied when looking at dodgers: a narrower dodger creates less action than a wider one of similar configuration. Sling Blade style dodgers are narrower than a 4/0 Seps.
Take a breath, as the rest of the article will make more sense. Now comes the new fun hotness.
One of my favorite sayings about fishing: what isn’t tried, won’t work.
There has been a smattering of discussion the last ten years or so about dual dodgers, the act of connecting two similar style dodgers together. But other than a novel alternative look, never an explanation of why a kokanee troller would do this when one will suffice. This season I’ve done quite a bit of experimentation with attaching two similar style dodgers, as a result there have been some definite bonuses in numbers of hookups.
Let’s look closer at the dual dodger, how it works and some theories on why it performs so well.
First, the unique action.
Starting with the most common dual dodger—linked 4/0 standard dual wave—these have been the best for overall action and productivity. Theories abound, but here are the facts. Dual 4/0's give a realistic fish mimicking swimming action. While the dodger in front is relatively restricted in movement, giving a slight 4 inch side to side swing/wobble, the back dodger (the recipient of free-swinging, full vacuum/pressure) swings widely, even more pronounced than when trolled solo. When trolled 1.1 to 1.6 mph (ideal speeds for dual 4/0s), the dual dodger closely impersonates a swimming fish. No solo dodger of any style mimics even slightly this same action.
Three thoughts on this:
One, it might appear to other kokanee as a feeding fellow salmon.
Two, as a novel alternative, because the dual does not mimic any other style of dodger, this can help get strikes in high pressure situations. If there are 50 boats using “standard” style single dodgers, where the flash and “thump” is rhythmic, the one twisting and flashing irregular may get the attention of pressured kokanee. This staccato movement gives unique “jittery” movement to lures without self-imparted action, primarily mini squids and trolling bugs.
Third, as this may be the most important, the rhythm of the swimming dual dodger is identical to a casual, non-threatened kokanee.
Dual 4/0 standards (Seps, Luhr Jensen, Dick Nite) should be your first choice, as they will be used the most often due to presentation speed, but there are two others with merit and have their place in your tackle trolling box. First are the weak waved style (#3 Sling Blade, 4.25" RMT Signature Dodger) which work better when trolling faster, from 1.5 to 2.2 mph. This speed makes the dual teardrop dodgers ideal for landlocked coho, which require a faster presentation than kokanee. For larger profile when targeting trophy kokes, try two 5.5" RMT Signature Dodgers in tandem.
Thin bladed trolling spoons make for excellent kokanee dodgers. Here I am looking at the #4 FST (For Salmon and Steelhead) thin blade trolling/plunking spoon by Yakima Bait, approximately 3 inches long. Hmmm. Diamond shape, two close pronounced waves...let’s rip open a few packages, remove the hooks, join them with a #4 split ring, take them to the lake, pull them at 1.2 mph and see what happens.
Bingo. Excellent tail swimming action, just a bit quicker “flick” of the rear dodger. Works optimum at 1.3 to 1.6 mph.
Rigging your dual dodgers is simple. Add a #5 split ring to the head and tail of the dodger, then add a small quality ball bearing swivel to join them.
When using double dodgers, keep this in mind- you are now trolling with double the weight, so there will obviously be more drop than when using singles. Where 3 to 4 feet of drop is normal with singles, expect 5 to 6 feet with doubles. Set your downriggers accordingly.
Summer Is Watermelon Time
All top kokanee trollers know the watermelon pattern (green stripe one side, matte cream center, pinkish red stripe on other side, half dozen large black dots spaced about the body) is one of the most deadly.
The great Buzz Ramsey says, “set out your best guess color choices for the conditions and let the fish tell you what they want”.
Let me share some interesting findings from this spring/early summer so far. I’ve tinkered a bit with altering the standard watermelon pattern by augmenting it with two types of UV tape. First, by covering 90% of the watermelon colored side of the dodger with transparent UV tape (from WTP, Inc) it changes the color spectrum dramatically.
The tape literally makes the watermelon pattern “blow up” with additional colors, plus turns the black spots to an interesting shade of red. The other side of the dodger, which is normally plain nickel, is covered with an oval of opaque UV (Delta Tackle) tape, greatly enhancing the flip side of the dodger. During 21 trips last season, in four different lakes, the enhanced watermelon produced strikes 2 to 1 over every other color dodger, including standard watermelon. On two separate occasions, the only strikes all day were on the enhanced watermelon. I liken this phenomenon to the theory behind the old “iris” Atlantic salmon fly pattern.
The originator figured if he used every color of the rainbow in his pattern, at least one color would be the right one for the condition to attract fish.
Let’s take the rainbow theory a bit further. Rainbow colored dodgers, when covered with translucent UV tape absolutely pops beyond belief with multicolor when hit with natural light.
Take the #4 FST (Yakima Bait) GRBO (glitter rainbow) or the Luhr Jensen 4/0 rainbow pattern and cover both sides with WTP translucent UV tape. Scary awesome. Fish both style dodgers either single or double, you won’t be disappointed.
All In Favor Say Eye
A trend is manifesting itself in my dodger choices. It seems the ones featuring life-like eyes are out producing my other dodgers, some days by leaps and bounds.
Apparently, the eyes on oblong and teardrop dodgers appears to feeding kokanee (we can only speculate, they’re not talking) as more of their brethren competing for the same limited food.
Anyway, I’ve been adding 1/4 to ½” diameter eyes to the majority of my kokanee dodgers, and it seems to be paying off with increasing numbers of takedowns.
A few extra kokanee tips:
- Pick up your gear (reel in) and re-apply scent every ten minutes. Doing so will up your strike/trolling time ratio, as fresh scent has been proven a zillion times more effective than the washed-out variety.
-Position your terminals above fish. Salmonids like kokanee cannot look down, only straight ahead and slightly upwards. Presenting your gear below them frequently goes unnoticed.
- Make frequent serpentine turns while trolling, at the same time vary speeds every minute or so. Kokes will react more aggressively toward irregular presentations (rising and dropping, bursts and deadening of speeds) than static, unnatural horizontal presentations.
Happy trolling, and don’t forget to take the kids!
- written by Bill Herzog