He certainly had to sail as a private ship at one point in the series, because he got into some mess, but it was some time ago when I read them, so I forget which one.
One of the best things about the series is how much music there is in it. The fact that officers set up string quartets and so on as onboard hobbies never occurred to me until I read the series, and I was told that it was absolutely true during the period.

yours, Peter T.