Michelle's probably right ... nobody will own up to it.
I'm sure we could come up with a dozen ways to keep this awful behavior from going on, but without enforcement, it's useless.
My most evil idea is buying an "AFC" (Away From Chair) tag from the deck attendant for the amount of time one intends to be gone. Max = 1 hour. More than that, stuff is picked up and put to one side. Return in time, and your card is not charged.
Further to Papa Bill's comments. The "What do you do?" people. I always say, "I'm on vacation, I'm not here to talk about work."
"I'm a writer" is a one-way ticket to conversational Hell.
One particularly obnoxious guy just would NOT let it be. I kept deflecting him. Finally, I left the table (it was open seating, first night out) for the ladies' room. The guy bored in on my husband. "Well, what DOES the little lady do that she's so mysterious about it?"
Queeg had HAD IT with the guy talking about the great deal he had, blah, blah, blah.
So, he smiled and said, "She is a proctologist. She has to see a@@holes every day of her life and doesn't like talking to them on vacation."