Could be adapted for boats ; A plumber invented a clamp that instantly fixes leaking pipes
Looks like a take off on something I saw used to stop a leak that was about to sink a submarine in a movie. That one was a big sheet metal (looked like aluminum) collar with a flange at each end that wrapped around about a 6" pipe and was secured with screws/bolts & nuts through the flanges. Something like that could easily be made smaller to use on boats a lot smaller than submarines.