Bunker spotters are even more frightening - there is a whole load of them at uk.rec.subterrenea (or something similar) who catalouge every nuclear bunker in existence as some kind of hobby?????
I too have heard about Box Tunnel - I thought that it had a nuclear power plant several stories below and was home to the Greys who will eventually take over the planet - or maybe I'm getting confused with the blues / reds?
But trainspotters in Devonport dockyard? Fools - everyone knows the strategic reserve is hidden in a tunnel in the West Midlands where it is guarded by Lord Lucan & Elvis. Don't you know anything?