Thank you, that's really helpful . What is working up? Getting ready to go to sea? The dry dock in Plymouth won't work as my officer needs to remain in Scotland. Can the duty crews go home if they live nearby when they are not duty? Who performs the maintenance, crew or dockyard workers or mixture of both?Maintenance periods can be anywhere from 3 months to 6 months or more, a full refit is up to 3 years but carried out in Guzz (Plymouth).
For a maintenance period the ships company stay with the boat with the duty watch staying in shoreside accommodation near the boat. The two boats in the patrol cycle have one at sea, the other doing maintenance ready to relieve the one on patrol. These boats have two crews, when the boat is at sea the off crew do stuff like courses, take leave, work inboard etc.
With 4 boats available, 2 are in the patrol cycle, 1 in extended maintenance period plus work ups and the 4th in dry dock in Guzz in refit.
Your officer could be on the boat that's just come out of refit and working up or in extended maintenance. A bomber queen will be able to give you a better insight, I was always on SSN's, far more interesting.