Continuity mistake: In the scene where the three Confederate soldiers are about to be executed for desertion, a blindfold is placed around the deserter on the right. It is a narrow strip of cloth covering his eyes. The camera pans to the firing squad and then back to the three men. The blindfold on the deserter on the right, is now much wider.
Continuity mistake: When Algren teaches a soldier to shoot, the soldier has a chin strap below his lip. Yet, in the next shot there is no strap. (00:19:35)
Revealing mistake: The Acheron fires many devastating blows on the Surprise and the effect is visible in close-ups and a wide shot. However, after Mr. Mowett yells, "Relieving-tackles on the tiller! You men collect the wounded!" there is another wide shot of the Acheron in the foreground and Surprise in the distance. In this shot Surprise has NO damage whatsoever! (00:11:00)