Thread: Interpreting sideimaging

I think it should look like this.

Distance from left or right to an object in the water is distant minus width of water column (roughly).

For instance:

If the left and right margins are set at 100 feet and the water is 20 foot deep:

1. an object appears on the left side at near the 100 ft margin.
2. That object would be roughly 80 foot away to left of the boat.
3. 100 (setting) minus 20 (water column) equals approximate distance to object.

I have marked and measured waypoints relative to the boat, and this is how the measurements came out.

MHAO. I have been wrong before.

I'm not familiar at all with these units, only what I have seen and read here. My thinking and understanding was that the picture scrolls from the top towards the bottom of the screen. Also the black is the water under the boat and to the right is the view to the right and to the left is the view to the left. If you look at the shadow of the large rock looking thing on the left picture you will see why I say that, the shadow is away from the centerline or the boat. On the right side you can see nearest the boat the detail is brighter which is shallower and as you move away from there it darkens which mean it gets deeper. If you look at the sonar view you can see that you are over hump, a steep drop off to the right side and the begininging of one to the left. I believe on the screen there is a boat at the top edge in the center of the black that point upwards and this is a birds eye view, so to speak. So my deduction is that if the boat is pointing that way, to the right is the right starting straight down at the black and going all the way to horizontal as you look further to the right. The sonor is like a MRI scan taking shots of small slices of information and stacking them one behind the other thus putting together the picture we see. The last shot is at the top of the screen and moves downwards as it adds on, like a regular sonor that puts the last shot on the right side of the screen and moves to the left. As you look down the page that is what has already passed behind the boat. I hope I haven't confused the confused which includes myself. I'm hoping to get one in the future and am gathering info also. Im sure that a real pro will step up soon and make us all understand.
From the bayou,
PawPaw "gene"

Don't tilt your head. Imagine setting in your boat, in the dark and all the water is now gone from the lake. You shine a spotlight out each side of the boat, 90°. You can't see under the boat. That is the black line down the middle. You can see everything the light hits. Anything standing up throws a shadow.

Here is how I picture it. The light blue is where the light (transducer signal) can see. Dark blue is where it can't.

Again, don't tilt your head. It is kinda like having an ariel view of the lake bottom, with all the water gone.

I agree with Ranger 690's post above. I just imagine that i am above the boat looking down at a dry lakebed. Things that appear left of the boat are on the left, likewise right. Remember that like your regular sonar, things down screen are behind your current location. How far back depends on your boat speed and scroll speed.

Humminbird rep told me about the folding paper theory when I was a Grizzly jigs. This folded paper theory essentially removes the water column from the picture (except directly below the boat). Maybe the rep will post the folded paper theory here and you folks will understand what I am trying to convey.

Folded paper sure simplifies the mystery.

I found some of my si images. I will take a picture of the fold and post it. It is how Humminbird explains the images. Simple once you see the folded paper.

Pic before fold