Just installed the HB 899 on my boat. This my first SI unit, and still do not understand everything I am seeing. Can someone please tell me if the bright white objects in the screenshot are rocks???? This was taken out in the middle of the lake, not close to anything. If so they must have been placed like this before the lake filled up with water. We do not have a lot of natural rock here in Louisiana. Thanks in advance.

Name: side image.jpg Views: 684 Size: 32.7 KB