Ok I reread the scenario I posted again to make sure I got the 'Physics' right.
1) In each post the wind was dead behind you, that without stabilization is death in a handbasket. The course needed to have been changed to ensure 'pressure' on the sail to keep the boat from swinging 'n tipping.
2) Changing your course 10 to 15 degrees with the wind almost on the stern will keep this top heavy boat from swaying as the wind no longer hits the sail from directly astern. The sea anchor could also have been used to take the load off your Rudder.
3) I've had a lot of passengers on board my boats over the years. Some of them have asked me what causes motion sickness. The answer will always be the same:
A) you are hung over
B) you haven't eaten anything
c) you have ear problems
D) you are just naturaly prone to sea sickness
E) You are on a Powerboat! I can't stabilize this boat like I can on a sailboat. The boat rolls are there is nothing above deck to keep this boat steady.
And that my friends is the answer to the riddle. Look at an Old School Trawler. Most of them have a teeny sail on a short mast.
No it's not a Jib, a Main, it is a Steadying sail and on a fat displacement hull. On a trawler it is also the difference between getting a net aboard or flying off the stern deck.
Yet the cross angle course by a Pro Helmsman will always be insisted on because having the wind on your ass is a bad idea as it will make the boat hard to control, cause a sickening roll or worse cause a pattern that may not be recoverable from if a wave breaks over your stern and floods your butt.
If the pattern when the wave breaks is the opposite, your stern may lift enough to nosedive the craft and cause a potential pitch pole.
But of course, this is just a story. We have no need to worry. Simular experiences happened years ago (before the lessons of the sea got pounded into my head).