Have probably posted this before, but seems fitting. Get there on time, or you might be entering on a non passenger deck with watermelons. That is what happened to me once.
This happened on Destiny out of Miami in 1997. We missed our flight due to fog, then another was cancelled. Ship was scheduled to leave at 4pm, we finally got there after 6. There were a total of 8 of us on a carnival shuttle that had missed flights. We didn't go through check-in, it was closed and the gangway gone. They pulled us in on a loading ramp with boxes of lettuce and watermelons.
Never want to go through a day like that again, and it was a miracle they held the ship. Have always went to the port a day early ever since.