Very many moons ago (like 1983) a colleague (cpl) and I (J/T) pitched up in the Eng mini to reset Boulmer’s TACAN.
The site was also used as visiting cadet accommodation.
They were leaving as we drove in and we got very smartly saluted.
As I was the passenger, I was instantly promoted to honorary AVM for the day. 
Hmm. You salute the quarterdeck boarding or disembarking, but I’ve not heard of saluting it when merely passing.
Just back from a week’s camp at Halton where the SOP is clearly not to salute officers coming in the main gate.
Is a CT thing? So casual observers can’t write & track the vehicle Reg of commissioned officers over ordinary enlisted?
The UN take a different tactic — salute all the vehicles!
Must be like dropping chaff for a radar!
does that rule about saluting apply to RAF aircraft? My old Trg Off said do but he wasn’t always the most trust worthy
They lie
I hope it doesn’t.
I am not saluting every time I climb on one of my heap of 
helicopters every time I have to fix something with them.