Garmin 7SV DI Interference

[MROBIT294]

Hoping for some technical help. I have a Garmin 7SV with CV52 xd mounted to transom on the starboard side of motor approx 15" from motor. Traditional and SI operate fine. When viewing DI and I am on the starboard side of boat, the image is fine. The second I move to the port side I get (2-3) horizontal bands of interference; usually 2. They are continuous horizontal bands while I remain on port side. Once I move starboard...they vanish. The motor is trimmed fully up while I get this. I have leveled the xd both with the boat and with the waterline and it is slightly below bottom of boat. I have even moved it from direct mount on transom to a stern saver thinking maybe it was hitting something with the boat slightly tilted (which doesn't really make sense). No luck. When viewing DI and Traditional on split screen, the interference is only on DI...any thoughts? There is another person at the bow and their movements do not cause this either way. I guess I could just fish from the starboard side! But really curious what this may be. Is it simply the slight tilt of the boat? Sorry for the bad image but I can only take a mobile photo of the 7SV screen.....you can see how the band just ends........ Thanks for any replies....

[Larry3215]

Very odd! Thats the first time I have ever heard of anything like that happening just because you move to a different side of the boat.

A few questions....

Are you actually in 5 ft of water or is that a zoomed in view?

What is the depth?

Does it do the same thing in deeper water?

How far does the boat tilt when you move to the port side?

Is there anything hanging off the back that could be drifting into the sonar beam, or even just getting close to the transducer, when the boat tilts?

[Larry3215]

Oh - and how fast are you going?

Are you using the trolling motor or the main or drifting?

[MROBIT294]

Thanks Larry3215! Yes, very odd. To answer your questions:

//That is actual depth on screen. Typically fish shallow.
//Happens at any depth.
//Speed is with trolling motor and approx 1mph. Main motor is trimmed up. Also happens while drifting.
//I have not noticed anything hanging off back. That was my first assumption as well. I will check again.
//Angle of list is a great point....not sure. I would guess 5-8 deg to port? I will see what happens when 2 people are at the stern.

Boat is an aluminum 2001 Ranger Cherokee 16' with a beam of 78". And I have always thought it was pretty stable.

But now you have raised a question in my mind; I was assuming any fittings on the transom where already clear of the xd because I leveled the xd with the boat and it works fine except for this one scenario. However, if the boat does heel to port when I move would that change the angle of the SI beam? Meaning it is physically pointing deeper, but now pinging a bit higher towards the surface of the water column and possibly hitting a live well fitting for instance? Not sure how to explain this or if even a possibility. But this is a CV xd which utilizes the blended SI for DI image..... I guess an argument for not thinking this as the cause is that wouldn't this then occur in rough conditions as the boat was heaving and swaying? No matter where I was? And I have not noticed this. Thanks!

[Larry3215]

No, the SI beams will hit, or not hit, the same stuff on the boat no matter what the list is. Same for the DI beam. It would have to be something loose that can shift position as the boat listed - like a tie down strap, fender, anchor, piece or rope, etc.

I doubt this is possible, but could the TD be lifted up out of the water or get very close to the surface when it lists? Thats the only other thing I can think of based on what you have said so far.

Very strange and interesting problem.

Sorry, interesting to me, but Im sure its annoying for you!

[MROBIT294]

Thanks Larry3215!

I will check out again this weekend. No chance of the TD coming out of the water. Mounted around 1/4" below bottom of boat.

I did inquire with Garmin support as well. They did not know what it was.

Ha ha ha, it is interesting to me as well....like I said, I can just fish from the starboard side!!! But I would like to figure this out.....I will post any additional findings but if something else comes to mind, please let me know.