I was fishing today and heard a high speed boat suddenly cut off. It was a couple hundred yards away. I could see someone in the water so I went over quickly. The guy had a inflatable life jacket (that worked) but his boat had "coasted" 50 yards or so. He was by himself. I pulled him into my boat and took him over to his. He was cold, but said he was OK. He had a dry coat, and blanket in his boat. He said he was OK to go back to the landing but I followed him, until he got in his truck. He didn't know what happened to throw him out. It was windy today but I could cruise comfortably in my tin tub.
So, my safety idea. I assume the reason boats don't have seat belts is because of the danger of trapping someone when capsized. How about seat belts with a "trigger" similar to an inflatable life jacket to release them if they're under water? The "trigger" would have to be located up high, so it would release even if someone's head was all that was under water. There are problem, like being trapped under a capsized boat after the seatbelt releases, but I think "something" to keep people in the boat could be worked out.