If it was 1980 vintage perhaps it was an MR1? When did it stop being called Jez?
From my first days on MR2s, mid 80s, it would have been:
'Tac Nav - Acoustics. Contact in Lofar (difar/Barra as required) 14 analysing!'
The subsequent classification would once again, as Ray has already stated, have been announced on intercom (hopefully the right one!) by acoustics - for which read the lead wet!
But the UK isn't in this game any more, so this conversation comes under the heading of nostalgia....
