Commander Bolton: Well, we'll know in six hours.
Colonel Winnant: I thought the tide came in every three hours.
Commander Bolton: Then it's a good job you're Army and I'm Navy, isn't it?
The me-109 have painted yellow fronts, this wasn't done by the Germans until after Dunkirk. Christopher Nolan has admitted doing this deliberately so the audience could tell the difference between the spitfire and the me-109 during the combat scenes.
There are only two women with speaking parts in the whole film, with 47 words between them.