Naval aviation consists of a number of "communities" in which aviators are expected to spend their careers, except for periods of staff shore duty or occassional sea duty. For example, fighter pilots of my generation ("year group" is the technical term) would anticipate orders to F-4 Phanton squadrons upon completing training, then a tour ashore as an instructor or other staff position, then back to the fighter squadron. Attack aviators followed a similar pattern.
There was some degree of cross fertilization, though, when fighter pilots were assigned to attack squadrons, say. This was done to faciliate cross training and ensure thecommunities didn't get too isolated.
There was one community that did remain fairly isolated: the Patrol community. Operating four-engined land based patrol aircraft, they focused almost exclusively on the anti-submarine warfare mission, a prime Naval mission during the bulk of the Cold War. Not having the opportunity of operating aboard ship made transition between patrol aviation and the at sea communities very difficult. Post WW II, an attempt was made to use land-based patrol aviators, familiar with the larger aircraft to be used for nuclear weapon delivery, to form the nucleus of shipboard heavy attack squadrons. It did not go well.
After leaving active duty in 1971, I immediately jointed a reserve patrol squadron, VP-94, the "Fighting Crayfish," home based in New Orleans. As a complete neophyte to ASW, there was a lot to learn, even on the ancient SP-2H aircraft we were flying. We deployed to Rota, Spain for our annual active duty and conducted patrols in the western Mediterranean. I attended a few Navy schools to get up to speed: Celestial Navigation School in Corpus Christi, and an Introduction to ASW at NAS Willow Grove, PA.
A move to Maryland for graduate school required a change of squadron, and I affiliated with the replacement unit for Patrol Squadron 68, the "Blackhawks" operating out of NATC Patuxent River, MD. This was a big change for a number of reasons. Most importantly, VP-68 flew the P-3A Orion aircraft. Another, more complex aircraft to learn! Also, instead of being hosted aboard a backwater reserve base, Pax River was, if any station was, at the forfront of Naval Aviation, by virtue of its hosting Naval Aviation's test operations, including Test Pilot School. While NAS Pensacola was touted as the "Cradle of Naval Aviation," Pax River was acknowledged as its graduate school.
I gradually became acclimated to the new aircraft and qualified as a navigator, and later as a tactical coordinator. I also qualified as a navigator NATOPS instructor, unusual for someone not from the patrol community.
After a move to the West Coast, I joined Patron Squadron 65 "GTridents" in the fall of 1979 and was quickly assigned to a "Alpha" crew. Aircrew routinely had to maintain currency in their primary flight position, such as plane commander, co-pilot, etc. As a NATOPS Tactical Navigator Instructor, I would administer the ground and flight evaluations for this position. But there was a much wider set of evaluations we had to meet, called "quals." There were two major differences: these were administer to the crew as a whole, and there were a lot more of them. Some were quite involved. For example, the "TORPEX" required a crew to detect, localize, track, and attack a submarine with a Mk-46 torpedo. Since expendable submarines were in short supply, we used an unmanned submersible target within an instrumented range in Hawaii.