Thread: Side Scan Sonar Help

Originally Posted by Humminbird_Greg

Marine181, do you get that same constant vertical line next to the centerline even when the boat is drifting with the motor off? If so, tan it is being caused by something to the left of the transducer that is blocking some of the left Si sonar signal. Try raising your motor up to see if it goes away. This is assuming that your transducer is mounted to the right side of your motor. If not, try posting some pictures of your transducer mounting.

Greg,

This was my first trip out but I want to say the motor was trimmed up. I was wondering the same thing, why the streak was showing up on the left side. I assume it was just prop wash. I will be taking the boat out again this weekend to see if I can get it to change.

Marine181,

Might also check for your livewell drain/pickup screen to see if its in the way. On my boat, I need to trim my motor up a bit.

Here are the pictures of the transducer mount.

You might try dropping the transducer a little lower ..... The tail end may be dropped down a little also..... The leveling depends on how the boat sits in the water, and I think others have described ways to make sure the transducer is level.

I agree with dfar ...

The line looks like prop wash because the second image at a slower speed shows the line less prominent ...

I also agree with Greg to allow the boat to drift to see if the line goes away ...

Rickie

Trim the motor up and try it again. Looking at your photo's it appears that your td is pointing down at the back, opposite of what it should be unless your boat sits bow down. The td should be parallel to the waters surface. I used a digital level to set mine, on the water I noted the degrees up or down fore and aft, then side to side. Once home I used the jack on the trailer to replicate the fore and aft attitude on the water and then set the td level. My boat sits low on the starboard side in the water, I don't remember the exact number. Let's say it's down 5 degrees on the starboard side, with the boat level side to side in my shop I set the td 5 degrees down on the port side. Keep in mind that the level needs to be in the same location when making adjustments that it's in when taking initial readings.

Thanks guys for all the info! Much appreciated! I will adjust the angle of the transducer to get it more on a level field. I will have some new pictures this weekend!

Marine181, i wouldn't worry much about your transducer tilted down in the back.i run mine like that also.its will give you better on plane 2d like that and also, I don't think you'll notice a difference on si with it tilted up.That interference that your seeing in the water column, on the left side sure looks like maybe something under your boat, in front of the transducer making air bubbles.