with no career beyond commander........
If they are General List (many Pilots and Observers are), they might go on to command ships etc. Indeed some take non aviation sea jobs (such as PWO or command of a minehunter) for a few years then return to flying. I remember looking at the biography page of the CO 0f 899 NAS a few years ago, and it said that before becoming CO his previous job had been First Lt of one of the Castle class patrol vessels in the South Atlantic. Even for ones that are not General List, they are Naval Officer first, which I imagine is useful when operating in a naval environment and the bigger picture (not just aviation) has to be considered. I remember having a discussion via PM with a WAFU regarding this issue.
Aviation is a key naval activity.
Anyway, my post made specific mention of operating from a deck. By this I am talking about the Chockheads, Flight Deck Officers, ATC types and others who will have to deal with the problems of dealing with a large number of aircraft operating from a small area that happens to be moving. They don't get as much experience now as they used to just a few years ago, since having fixed wing aircraft (with different procedures and problems to helicopters) embarked is increasingly rare these days. I seem to remember listening to a chockhead talking about this over a pint or two a few months ago.