"W.H.Smyth whose nickname was "Mediterranean Smyth" career ended as follows:

On 7 February 1824, he was promoted to Post-Captain, and in November paid off the Adventure, marking the end of his service at sea and his turn to a life of literary and scientific pursuits."

Yes, but the OP said 'I'm rereading James Norman Hall's Doctor Dogbody's Leg..." - W. H. Smyth was just mentioned in passing in a later post. James Norman Hall was an American writer, so all the references to the (British) Royal Navy and its customs are irrelevant:

https://en.wikipedia.org/wiki/James_Norman_Hall