Transducer angle problem or electrical interference. Please look at the pic!

[scott__henning]

your arches are lopsided, so check that your transducer is horizontal. its not a huge issue however.

the clutter looks about normal, always run the sensitivity on auto, does a good job

[greggo]

You might not be aware, but the auto setting is based on further input. Go to settings, Adjust, Auto sensitivity. You can adjust it while travelling until you get the picture you're happy with. Mine varies a lot depending on PPBay, WPBay, fresh water, salt water, dirty water, etc...etc.

[re-tyred]

Most issues with any sounder at speed are either, air bubble or acoustic noise from the propeller, hull or even water crossing the transducer face at speed. You don't have much of an air problem as that causes gaps. I suspect this is acoustic noise , and mine has the same issue. I don't worry about it too much as I go slow when looking for fish and I still get bottom at 20knts just a bit of a messy screen like yous. However if you want to fix it try your sensitivity settings and noise settings. Be aware that you may degrade you fish finding quality. Stopping the problem at the source is about transducer location, usually further from the motor/prop or if it it the hull vibrations then a block of wood or hard rubber between the transducer mounting and the hull. Often moving the transducer further away from the motor ends up with it being in and air bubble area as a tinnie doesn't have much room on the transom. Glass boats don't seem to have as much problem as they don't vibrate the same as a tinnie.

[Kestrel]

Thanks for all of the replies and suggestions! They have given me quite a few ideas and clues about what I can do.

Much appreciated!
Kestrel