Muffy Aldrich, whom I'm inclined to like because of the people who hate her, had a discussion on her blog about boat shoes. Her readers chipped in on various subjects including whether it is okay to wear them with socks. Spoiler: it is!
It struck me that there is an interesting historical irony here. The practice of wearing boat shoes without socks initially sprang up as a form of rebellion among upper-middle-class teenagers. I know this because I was one of them. I'm not sure when it began. It was well-established by the time I came along in the last-half of the 1970s.
"Rebellion" is a relative term. Upper-middle-class kids in those days did not buy their own clothes. They went shopping with mommy (or, if you were Canadian as I was, went shopping with "mummy"). We wore more or less what we were told to wear. Rebellion, then, could only mean wearing what you were told to wear with a certain flair. Thus boat shoes and loafers were often worn without socks.
This information got published in The Preppy Handbook and it became a style to copy. Ironically, what was initially a rebellion became a rule. And now there are people who insist you can't wear socks with boat shoes.
Worse, there are people who will advocate wearing those horrid little sockettes that won't show. Nothing could be further from the preppy spirit. The right choice is a rough wool sock. (Why wool? Because it's still warm when wet.)