Character mistake: Following McQueen's viewing of Naval Shipmate Attenborough's corpse, he then fails to recover the decedents dogtag; a United States Military Protocol.
Factual error: The uniforms worn by the engineering force are from the wrong era. Prior to 1941 the left arm rates had the head of the eagle pointing to the wearer's rear. Steve McQueen and the rest of the Engineering force rate eagle head is pointing forward, which is from WW2.
Factual error: When Holman and Frenchy go to the Red Cattle to buy Maily, they are wearing undress whites. Since they are on liberty, they should be wearing dress whites, like Holman was wearing at the beginning of the movie.
Factual error: When the San Pablo's main gun is firing at the junks, the gun does not recoil at all.
Revealing mistake: When the US Navy engages the enemy at the blockade on the Yangtze River, during combat scenes, a sailor's (prop) bayonet wiggles on board the San Pablo.
Other mistake: About 1 1/2 hours into the movie, Ensign Bordelles, in the courtyard of the American facility in Changsha, prepares his shore party to march back to San Pablo with the Chinese military escort on either side. The Ensign lines up his men and orders, "Detail, forward March." The Chinese soldiers, unlikely to understand a word of English, also move off in lock step with the Americans.
Chosen answer: It's a pun on the name of the boat which features in the film: the fictional U. S. Navy ship USS San Pablo. The sailors on the San Pablo call themselves the sand pebbles.
Sierra1 ★