Your 2d sonar image is from a 3D cone shape. If you are in 25 feet of water that cone covers more area forward of the transom (under the boat) than if you are in 10 feet of water. So throw a buoy behind you, do a U-turn and go over from the opposite direction and throw a 2nd buoy. Try fishing in between them.

There is also margin of error left and right because you have a 3D cone and a 2d image. That pile could be 5 feet to your side. So be sure to fish all around your buoy. Good luck!