Factual error: In the US Navy, liberty (what civilians usually call "shore leave") does not commence at 6:00 in the morning. It commences at 1600 (4:00 in the afternoon) and you have to be back on board by 0700 the next morning. Weekend liberty commences at 1600 Friday and expires on board at 0700 Monday.
Factual error: None of the sailors has either service ribbons or rate insignia on his uniform. Even if they were all fresh out of boot camp, they would have had to have at least a rate insignia.
Factual error: One does not simply walk (or run) onto or off a U.S. Navy ship. Every individual coming aboard stops at the head of the brow (gangplank to civilians), faces the ensign (flag) at the stern and salutes, then turns to face the officer of the deck (OOD), salutes again, and says, "Request permission to come aboard, sir." The OOD returns the salute and says, "Permission granted," whereupon the individual steps off the brow onto the ship. A similar procedure is used when leaving the ship, with the individual requesting permission to go ashore.
Character mistake: In Frank Sinatra's scene in the taxi cab, when the girl is singing "Come Up to My Place," he rolls the cab window down and when he rolls it back up, he catches the front of his hair (the quiff) and has to roll the window back down to release it.