Fish relate to docks and it is nice to focus on the areas with the most fish. The first image is the docks.
The next image is the fish and docks circled. The posts have long shadows and the fish have short shadows and both are white dots.

Always use the 455 kHz frequency when scanning shallow since it's cone is closer to the water surface so it "sees" farther in shallow water.
Go Fishing, the Clock is Ticking