Humminbird Down Imaging: finding fish and structure beneath your boat in a whole new way!
Dr. Jason Halfen
Professional Walleye Angler
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One of the new enhancements for 2010 model year Humminbird Fishing Systems is the addition of Down Imaging, which provides anglers with a high-resolution picture of objects directly underneath the boat. While this area is also covered by traditional 2D sonar, the high-frequency sonar used to collect the Down Image provides a much clearer picture of those below-the-boat objects, providing the angler with a more detailed representation of objects, structure, and fish that the boat is passing directly over.
I have been given permission to run a pre-release version of the Down Imaging software, and to share some of my field test results of this technology with you. Below are some Down Images and combination Down Image/Side Image screen captures that I've collected, which start to demonstrate the power of Humminbird Down Imaging. I'll be augmenting these results in the coming weeks, as I become more familiar with the software and its options.
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To get the ball rolling, here's a Down Image (collected using the new Amber 1 color palette) of a large group of fish sitting in some slack water in front of a wing dam on the Mississippi River. Fish do not appear as arches in Down Imaging, due to the differences in sonar beam shapes between the 455 kHz Down Imaging sonar beam (which is quite thin) and traditional 200 kHz 2D sonar cone. This Down Imaging view is historical, in much the same was as a traditional sonar view, with the newest returns on the far right and the oldest on the far left. At the left end of this Down Image, you'll see the tip of the wingdam, with the group of fish continuing throughout the image.
Here's a 2-way split screen with traditional 2D (200 kHz) sonar on the left and Down Imaging on the right. I like this view because it again demonstrates the enhanced resolution of objects that Down Imaging provides relative to traditional 2D sonar. The 2D view on the left illustrates the presence of two piles of...something. Even a lengthy study of this iamge fails to provide significant insight into the identity of these objects. A quick glance at the Down Imaging view on the right demostrates that these objects are two piles of woody debris...sticks. Individual sticks protruding from the piles are clearly visible In a backwards sort of way, I confirmed the identity of these objects as woody debris...by snagging a bunch of sticks while pulling 3-ways and cranks as I collected this screen capture.
Down Imaging is available as a stand-alone view, or in combination with other sonar views including a Down Imaging/Side Imaging split view, a Down Imaging/2D sonar split view, and a 3-way split view that incorporates Down Imaging, Side Imaging, and the traditional 2D view. Here's a 3-way split screen view that illustrates one large, bottom-hugging fish that can be identified in all three sonar views. This fish is noted with red arrows in the Side Imaging view (right) and the Down Imaging view (upper left), and by the blue arrow in the traditional 2D sonar view (lower left). I'm running the 2D sonar in "Max" mode in this particular view to maximize the amount of information displayed by the200 kHz 2D sonar. While the fish is poorly resolved from the bottom in the 200 kHz view, it is cleanly resolved in the 455 kHz, Down Imaging view.
Here's another 2-way split screen with traditional 2D (200 kHz) sonar on the left and Down Imaging on the right. This screen captures further illustrates the enhanced resolution of objects that Down Imaging provides relative to traditional 2D sonar. The 2D view on the left shows a piece of standing timber extending ~ 10 feet off the bottom (this thing must be COVERED with jigs and rigs!). The 2D view shows one prominent piece of the tree that is leaning downstream, with a smaller piece forwrd of that one large piece. A quick inspection of the Down Imaging view on the right shows that the single large portion is actually two long, parallel pieces of wiid, with another long branch on the upstream side and several smaller branches that are more horizontal than vertical. The fine structure of the tree is clearly visible in Down Imaging, and absent in the traditional 2D view.
One more split-screen capture for now, showing the combination of Down Imaging on the left and Side Imaging on the right. This particular object is a closing dam, with about 4 feet of water movoing over the top of it. The bottom in this area is hard-packed sand, with the rocky closing dam washed clean of sand. This change in composition is apparent in both the Side Image and the Down Image, where individual rocks are apparent due to the change in the texture of the images associated with tjhe closing dam. The small object (perhaps a rock or a stump?) that Down Imaging shows forward of the dam (noted with the red arrow) is also present in the Side Image (also marked in red), although the Down Image shows thos object much more clearly than does the Side Image.
Down Imaging is going to be a powerful new source of information for objects, structure and fish that are present directly beneath the boat. Be sure to check back here often for new Down Imaging screen captures, and for ways to use Humminbird Down Imaging and Side Imaging to help you catch more fish in 2010!
