Well.....it depends. How's that for a definitive answer? Depending on how you use your SI, you should be able to see some of what's there. I think there are two separate beams of SI....one shoots down/sideways in a cone slice, and the other shoots out in a rectangular slice(which should show you what's higher in the water column). When I scan dock cables, I can see the concrete block and the cable going up, but can't see it going all the way to the surface. Try asking this in the main "Fishing Electronics" forum and you may get a better answer.