The above images shows several mooring blocks. Two are abandoned. Mooring block location, recovery and recommissioning are available. If you select the image it will expand to show a larger area. This image was taken on a 200 meter swath width 340khz search sonar.
Mooring & ANchorage Hazards
The above image shows a survey of a known anchorage area. Obviously there are numerous hazards. In this image you will see a large section of the I-90 floating bridge that sank in 1994. This debris is several miles from where the original bridge broke apart and would not normally be expected to be here.