SI picture

Why do I have the line in the middle. Any tips to even out the brightness?
Attachment 391683

To be clear... this circled line?Attachment 391701

Sent from my SM-G960U using Crappie.com Fishing mobile app

Line in the middle is your boat path, the width of that line is the surface clutter setting. The black to either side of the line is the water depth. The clarity between the two sides could be one of two things, either the SI transducer is on the port side of the outboard and the trim depth of the skeg is blocking the right side view or the water is simply deeper on the starboard side of the boat and you are traveling along a break. Judging by the depth of the water on the starboard side of the boat due to the surface clutter I am going to go guess that your transducer is mounted starboard of the outboard and the water was deeper on that side as well in this picture?

How about a reflection off of whatever is blocking you on the left side. You have some blockage there. How's that for a guess??

IMO that line is the edge of the bottom of the lake on the right side. If you look closely the dark area to the right of that line actually has some "texture" to it, meaning it's the bottom. I think the better question is why is there such a dark streak past the bottom contour, extending to the right. It could be the position of the boat on a drop off. The "line" fits as being the bottom if you look at the center line of the water column. The interference looks to be to the left of the ducer.

The void directly beneath the boat is the area where the cone angles are separated. SI fires off a cone to either side, with a void in the middle that is filled with 2D or DI.

The black area off the right is either, as mentioned, a drop off/ledge or something is blocking the transducer. If you turn around and see it on the left side, it is a drop off, if it's still there on the right then the transducer is blocked.

It almost looks like it dips and comes back up where the brighter line is towards the middle, like you are just off center of a creek creek channel, which would make sense, as the closer ledge is going to cast a shadow, explaining the dark area in the channel.

It is also possible your transducer is not level ... if it is tilting to the port .... left .... side, that would cause the left side to be brighter.

It is also possible you have a bad transducer or a problem with the unit.

I would check level first .... put a level on your transom while moving at scanning speed to see if the boat is riding level .... if it is, then level the transducer.
If the boat is not riding level it gets a little more complicated to get the transducer level. You would have to have the boat sitting at the attitude it is in the water .... and then level the transducer.

I'd guess your main motor as well if your getting this all the time. Try lifting your motor up while using your trolling motor and see if the line goes away.