I had this problem last time out and couldnt figure out what was wrong.
Ive not changed the transducer angle.
What it does is as its looking forward and working fine, all of a sudden the screen starts rotating down and up.
Like the bottom goes away then comes back up and just keeps flipping like this up and down.
Im taking it out tomorrow and hope to get a video of it but does anyone know a fix or why it may be doing this?