When I was in the Navy 1965/70 a typical exercise at sea could be:
- Departure from home port, e.g. Gothenburg.
- Arrival at exercise area to e.g. hunt and destroy an enemy submarine. The area could be 30 n.m. long and 15 n.m. wide off normal sea lanes in the Kattegatt. 450 square n.m. is a big area to search for a small sub with our sonars. The sub to avoid being found could just drop to the bottom and stop.
- I remember we were going up and down the area at different speeds/courses all the time, i.e. changing course often. Speed could vary from 5 to 25 knots.
- The CO was of course in the war room below the nav.bridge wondering, where the enemy sub could be leaving the navigation and collision avoidance to an officer on the nav.bridge.
- The engine rooms were fully manned with all four boilers running needing adjusting all the time as power output changed, people looked for leaks, etc.
- Nobody was sleeping aboard.
- At the end of the exercise we returned to the home port and slept.
- I really wonder why the FITZ changed course in the middle of the night in a busy sea lane full of ships going to/from Yokohama with the CO asleep in his suite. What kind of exercise could it have been?