Thanks for the update. I did the survey, talking from 7 years of online experience. Doing sea sorties I was lost many times and dealing with engine damage was too much on the stress of telling my position and managing fuel. I would say I`d want the whole thing to be accessible. In my opinion the casual flightsimgoer could be very much afraid of navigating anything related to sea/ships even if the map is the smaller sort.
I know it sounds patronizing but keep it simple and do the easy stuff first.