whereas a navy crewman is expected to nav day
Without wishing to get into a pi**ing contest between the Wsop and Navy crewman jobs, if all your job depend on is being able to navigate then there is no contest.
The RAF Wsop has to be able to a quote form the RAF careers website " responsible for all aspects of aircraft loading, both internal and external. With the Chinook triple-hook system and capacity to carry 40 fully equipped troops, the crewman has to be able to fulfil a number of roles – not only operating the aircraft’s communications, self-defence and weapon systems, but also planning missions and servicing the aircraft when it’s operating “in the field”.’
A little bit more involved I would say. Of course there is also the opportunity to move to another aircraft type and do a completely different job, something the RN cannot offer.