Underwater obstructions (dumped rubbish)
Hi Boaty. The technology is already with us, Sonar is used by carp fishermen, in their bait boats. Transponder in the hull with a transmitter to a shore based screen, shows depth and the bottom contours, also what depth the fish are swimming!!! not expensive either. Not great clarity, but enough to see whats going on below.
Mark
Mark
Etherow Model Boat Club
がいいねしました NPJ and RNinMunich