You know, when I was in, the Quartermaster was still required to use a sexton and to validate position using it.
We knew we could see them using it whenever the ship shut down all receivers and transmitters, I forgot what they use to announce, but if we wanted to see the Quartermaster work we could go up at that time to see them in action.
Our ship was nuclear capable, it had to have all the equipment required to enable it to work even if all the satellites were toast.
Was it “Darkened Ship” by chance?