I thought the same thing. Bruises on her wrists, knees and ankles sounds exactly like what would happen to someone trying to climb back into a boat.
On a small boat, perhaps but not a 60 footer that would have a swim platform on the stern.......
Or they could be the result of her being repeatedly hit by someone with an oar or a similar item to prevent her from climbing back up on the vessel.
I fell off our 40’er, between the dock and boat. I went under the boat, opened my eyes to find light, and tried to orient myself to the swim platform. It could not have been 10 seconds, and my husband had the ladder out and ready. Here s the thing, I had bruises all over me the next day, my muscles were exhausted probably from panic and I was so desperate to get in the boat, I am sure I was flailing. I can only imagine what even a five minute episode would do to the body. (I would like to add, we had taken a 12 week Power Squadron class and the instructor said a boater WILL fall off the boat someday and told us what to do. When I went off the boat, everything we were taught immediately came to mind, while I was momentarily trapped under the vessel. That instructor and class saved my life.).