The girlfriends introduce the Stooges as 'Dinky', 'Blinky' and 'Stinky'. But for the rest of the film, they're back to using their usual names of Moe, Larry & Curly.
Larry's line is cut off when the camera goes over to Moe talking when the Stooges arrive on the enemy ship.
The binoculars that Moe use disappear after the shot of the dog paddling in the water.
Moe writes another tally on the wall when the second soldier is knocked out, but another one mysteriously appears as there is no explanation why.
Another smashing sound effect is heard when the captain falls back on the couch before the flower pot knocks him out.
The actress playing Moe's girlfriend apparently did not enjoy kissing him, as she is frantically wiping her mouth off.
Before Moe throws the railing on the German spies, Moe almost says "Nazis.", where he was supposed to say "Ratzis."
The "by" on Jules White's producing and directing is missing in the opening titles.
When the torpedo crashes into the ship, the water stops after a short time. Unlikely that would happen when that part of the ship is under the water line.
The person Curly knocks out is slimmer than him so the uniform Curly takes from him would not fit Curly.
At the end, Larry closes his eyes a second or two before the Stooges are hit with water.
When the Stooges board the Nazi ship, on the bottom of the screen, you can see the shadow of director Jules White's hand waving, cuing the actor playing the soldier to come down the stairs. This happens when the Stooges duck into a porthole.
When the captain says the line "What men? We have no new men." The actor says it in his regular voice instead of a German dialect.