What is the most awful thing you have ever seen anyone do on a boat?
Well, there was the time, on a yacht that I occasionally raced with, that the owner was entertaining a lady friend.
In the aft cabin, on the bunk.
A lady friend who was unknown, as things transpired, to his wife.
That would be the wife, who unexpectedly came to the boat and heard the goings on in the aft cabin.
She, in a possible thoughtless response picked up the quite heavy, adrenaline gives one unusual strength, life raft in its valise pack from its stowage on the deck and hurled it down the companion way. And pulled the activation string until it activated.
The blood curdling screams from the owners lady friend as she tried, naked or almost so, to escape the rapidly and noisily inflating orange monster were, according to witnesses, the stuff of legend.
The boat was sold shortly thereafter, and apparently there were also divorce proceedings.
I was at the helm of a nice new Beneteau, 40-something. The owner/skipper had had a couple of drinks, stood in front of the helm, looking aft, and turned the wheel so that we were heading right at another boat. I was reluctant to overrule the skipper, maybe he intended some kind of dick move to scare the other boat.
But I decided to throw the helm over and we narrowly missed the other boat. I don't remember the skipper/owner having any big reaction, but he might have been a little surprised to have passed so close to the other boat, and didn't seem to know them.
Another time, I was sailing a Capri 22 on starboard tack when a large sailboat approached under engine power. It looked like a serious voyaging vessel, so I assumed that they would understand the rules of the road and turn to pass astern of me. But they did not turn, so I tacked off . I guess they saw me just before I tacked, because they turned also. The net effect of my tack and their turn was that I was about to be sliced in half. I tacked again, just in time, and ended up on a parallel course.
A few days later, I saw that same large boat on a mooring. I got the name and did a web search. It turned out that the skipper had a web site and blog. They had arrived in San Diego after sailing through the Northwest Passage; these were serious, experienced sailors. I emailed the skipper, who remembered the incident and apologized. He and the first mate had been looking at charts, planning the next leg of their voyage and hadn't seen me.
So even the most skilled and experienced sailors can make a mistake.