Deliberate mistake: Morse code takes a lot longer to type out than the captain of the Dallas seems to need. Likely "compressed" because otherwise the process would be quite dull, but still.
Deliberate mistake: The torpedo hitting the water dropped by the Russian Bear Foxtrot, and the one dropped by the Americans are the same piece of footage.
Chosen answer: They use it to wipe the grease pencil markings off the screens.
We called it "the Duty Roll."