Tommy and Gibson under the mole (Dramatic Irony)
After being asked to get off the destroyer that is filling up at the mole, Tommy and Gibson climb onto the mole beneath the dock itself. From there, they listen in on Bolton and Winnant discussing the hopelessness of the situation at Dunkirk, and learn just how dire things are. The viewer sees that Tommy and Gibson are hiding under the mole, but Bolton and Winnant, as well as the other soldiers looking to escape the beach, do not. Thus, the viewer knows more than some of the characters.
Peter locks the shell-shocked soldier in the cabin (Dramatic Irony)
After Dawson, Peter, and George have taken the shell-shocked soldier aboard, Dawson advises the soldier to go down below. Escorting him down there, Peter locks the door of the soldier's cabin, but neither the soldier nor Dawson knows that he's doing this. Thus, there is dramatic irony in the fact that we know something these characters do not.
Peter tells the soldier that George is alright (Dramatic Irony)
After George dies, pushed accidentally down the stairs by the shell-shocked soldier, the soldier asks Peter how George is doing. Peter lies to the soldier, not wanting to upset him, and tells him that George is going to be alright. While the viewer knows that George is dead, the soldier remains in the dark about it.
Staying outside (Situational Irony)
Tommy, Alex, and Gibson all board a destroyer that is set to take them home. When they get on, Gibson remains outside in the cold rather than going below deck with the other soldiers and getting some tea. Alex is skeptical of Gibson's decision to stay above deck, suspicious that he is up to something. Ironically enough, Gibson’s decision to remain outside is what allows him to save the other men on the ship by opening the hatch from the outside, freeing those below deck from drowning after the destroyer is torpedoed.
