When I did a tour of the Constitution, the tour guide told us many shipping sayings, one the gunners had hammocks above the cannons, where they slept, at port, the “girls” would come on to see the men, if they got pregnant, the baby was a son of a gun
three squares, = the plates were square, thee squares a day. Something with the plates being stored on end, they wont roll out of the stg at sail.
mind your P’s and Q’s, = pay your bar tab for your pints and Quarts. Dont run up a bill at ports that you don’t pay.