Quote Originally Posted by uaagr View Post
The boat entered choppy water or was hit by the wake of another boat?
I concur .... based on the bottom contour has wavy lines & they start at the same point where the "dot" fish become "wavy" fish. Could possibly also be that the boat was slowed down some by the waves, dragging the dots out across the screen because they were in the sonar ping longer due to the slowing of the boat.

... cp