This picture was taken on board one of our customer's vessels while exiting the port in Marseille. The chart display on the right shows the narrow channel passage with very little water below the sonar. The FarSounder FS-3DT sonar detects them as well. The ship was operating in just a few meters of water. The sea floor is mapped to greater than 8 water depths and the piers are detected as in-water targets.
Note: The FS-3DT has since been replaced by the FarSounder-500 which features longer range performance, redesigned electronics, and better software all in the same form factor.