I recall a story of someone getting mowed down by a power boat in Biscayne Bay. I don't think the boat stopped (it was on full plane, similar to the H-18 story)

We almost got plowed by a 50 powerboat (being operated by Coast Guard Auxiliary) at Hiram's on a spin run. They didn't anticipate our speed and turned into us as we were approaching to cross their stern. Crash gybe at about 15 feet of closure.

Sure, they weren't on a full plane, but it still scared me out of my harness...