Finding fish in cold water, part 2: Using Humminbird's Dual Beam sonar for vertical jigging
Navigation:
One of the most frequent questions that I receive in person and by e-mail is, "with all of the emphasis on high resolution imaging provided by Side Imaging and Down Imaging, why would a person ever need to use "traditional" down-looking sonar?" This is a fair question, as the detail provided by Humminbird's Side Imaging and Down Imaging reveals underwater objects with picture-like clarity, in ways simply not possible with traditional sonar. Nevertheless, traditional down-looking, or 2D sonar, is far from being sent out to pasture; in fact, there are some applications in which traditional sonar excels, and is able to outperform high resolution Side or Down Imaging. One of these applications is real-time monitoring of a vertical jigging presentation, which allows the angler to follow their bait as it hovers above the bottom, see the fish as they interact with the bait, and even watch the hooked fish travel to the surface as the angler reels them in. In this article, I'll describe how I use Humminbird's (traditional) Dual Beam sonar to vertical jig for walleye and sauger in cold water.
Dr. Jason Halfen
Professional Walleye Angler
Navigation:
Finding fish is one of the many strengths of Side Imaging. However, when actively fishing for those fish, I will typically rely on the (traditional) Dual Beam sonar capabilities of my bow unit, a Humminbird 858c. Why Dual Beam sonar? Let's take a look at a Dual Beam screen capture, and then I'll explain why I rely on this traditional sonar for catching fish while vertical jigging.
I'll start this lesson by referring back to a screen capture in part 1 of this series, which describes how I use the Sharpness feature of Humminbird's Side Imaging fishing systems to identify large concentrations of bottom-hugging walleye and sauger. That screen capture is included below; the image shows a deep flat (20-25 feet deep) that is downstream of a much deeper wintering hole. This particular deep flat is littered with fish, which appear as bright white spots on both the left and right Side Images.
First, a bit of context: my bait is a 3/8 oz VMC Neon Moon Eye jig, rigged with a Trigger X 3" walleye minnow. Even this rather compact presentation is easy to follow using Humminbird's Dual Beam sonar, as shown above. This sequence begins with my jig falling to the bottom. Once I made contact with the bottom, I engaged the reel and lifted the jig just off the bottom. My normal cold water vertical jigging stroke is to give the bait a quick hop followed by a long hover just off the bottom. You can see the result of the quick hop-and-hover jig stroke: a fish approaches the bait, inspects and then eats it, followed by a free trip to the surface for an eventual release.
Why Dual Beam (200/83 KHz) sonar and not high-resolution Down Imaging or Side Imaging? This diagram explains it best:
Side Imaging and Down Imaging sonar signals leave the transducer as very thin beams, about the thickness of several sheets of paper stacked on top of each other. For a jig to provide a consistent return in Side Imaging or Down Imaging, it would need to remain within that very thin beam for a significant amount of time...which is next to impossible under real-world fishing conditions. Because Dual Beam sonar provides a much wider coverage of the bottom and the water column beneath the transducer, it is much easier for the jig to remain in that covered area, and therefore be displayed for long periods of time on a sonar display.
Let's look at another example of a vertical jigging presentation using Humminbird's Dual Beam sonar. This screen capture shows two jigs being fished simultaneously in the water beneath the transducer, a fish hitting one of the jigs, and evidence of the unfortunate reality that we don't catch every fish that bites!
It is convenient to think about traditional sonar energy being produced by the transducer in a cone-shaped pattern. The sonar cone angle defines the amount of bottom coverage that is provided by a particular sonar frequency. Humminbird's Dual Beam sonar comprises two separate sonar frequencies, each transmitted with its own cone angle. The 200 kHz frequency has a narrow cone angle, and provides high-precision information about water depth and objects that are in the narrow sonar cone. The 83 kHz frequency provides much wider coverage than the 200 kHz beam, making it easier to identify fish and other objects in the water column. The two frequencies work hand-in-hand to provide the angler with detailed information about depth and objects in the water column beneath the transducer
Humminbird's Side Imaging and Down Imaging technologies are vital technological tools for anglers as they search for fish and structure. However, when it comes to catching those fish, it's hard to beat the power of Humminbird's traditional, Dual Beam sonar. Be sure to try using Dual Beam sonar the next time to put your favorite vertical presentation to use; I think you'll be pleasantly surprised at how easy it is to follow your baits and the fish that are interacting with them.
