Fine tuning your chart speed in a Humminbird Side Imaging system
I posted a reply to a thread last night that described the proper relationship between chart speed and boat speed to achieve the clearest Side Images from your Humminbird Fishing System. I thought I'd augment that post with a few additional screen captures that illustrate how your Side Images should, and should not, look.
First, some background. I collect many of my Side Images on Lake Wissota, a 6000+ acre reservoir in western Wisconsin. Wissota has a very active fish crib program (for all of its mega crappies) and these articifial, square-shaped structures are great targets for Side Imaging, and for fine tuning your display. If you read In-Fisherman magazine, you may have seen this Side Image that I collected. It contains a row of fish cribs and a sunken boat.
Last edited by Jason Halfen #511 : 11-04-2009 at 12:29 PM.
It is important to correlate your boat speed with your chart speed. At my normal scouting speed of 4-5 mph, I'll run a chart speed of 2-3 on my 1197, and 4-5 on my 997. This combination of chart speed and boat speed produced the clearest, sharpest Side Images for me. For example, check out this row of cribs that sits at the edge of a shallow shelf. The cribs are all square-shaped, undistorted, and clear in the Side Image. These were imaged with my 1197 at 5.3 mph, with a chart speed of 3 and a Side Image range of 110 feet L and R.
Now, here's a portion of the same row of cribs, imaged at the same boat speed, but an inappropriately fast chart speed (9). Note that the cribs have lost their crisp definition that was obvious in the Side Image above, and they have started to become elongated (moving from squares to rectangles).
Finally, here's the row of cribs again, imaged at the same boat speed but an inappropriately slow chart speed (1). Note that the cribs are quite compressed and (again) have less definition than they had in the first Side Image above.
A little bit of trial and error will help you figure out the correct chart speed for whatever speed your boat is moving at. As long as you remember to slow your chart speed if the boat slows down, or increase your chart speed if the boat is moving faster, you should be able to collect crisp Side Images with your Humminbird Fishing System at any speed between 1 (or less) and 6 mph.
Most of my work (and all of these screen captures) uses with the blue color. I have not had enough time on the water since the release of the new Amber color palettes (Amber 1 and Amber 2) that are part of software version 4.70 to know if I like them better than blue.
I don't seem to have that problem. In fact, I fiddle with the instrument defaults surprisingly little....using instead the settings for sensitivity, contrast, etc that are set at the factory.
Fine tuning your chart speed in a Humminbird Side Imaging system
Linear Mode
