rickie
chart speed was all set at 4. boat speed was 5 on the 1st shot but I tried to keep this and direction steady after it. plenty of shots with a bridge that looked as though it curved left and right made me see this lol

Don
Around the bridge on the 2nd shot I should have picked up rocks on the channel drop. The last shot I can start to see them better from working in SI settings. I think that direction of travel over a target also plays a part in what shows up as you can see in the angle of the bridge in the shots.

Have you noticed this in shots you've taken? Was wanting to go out this morning but I had to do other things so was not able to check it out more.