I know this this might seem daft, but, I was idly wondering whilst gazing
at my carnation shaped propeller if a second, narrow angle depth gague with
it's transducer shooting horizontally forwards just below the water surface,
would give advance warning of an impending prop repair? (alarm set at, say,
40 feet). How would the sonar cope with seeing (hearing) the water surface
and waves? would 2 sonars interfere with each other?
Steve