Here is a ping 360 shot of a sphere that was used to support an anti-torpedo net, that was protecting a dam in WW2. The other photo shows the sphere holding the net in place. The net and spheres were sunk at the end of the war and lay undiscovered until Prof. Bob Stone and a team from the University of Birmingham found them.
The bottom sphere shows the “sonar shadow” very well. The sphere at the 3o’clock position is more corroded and the return not as crisp.