"The Ministry of Defence admitted it had been conducting exercises involving surface ships and submarines in Falmouth Bay" when both types of vessel are involved you can be damned sure that they will be using active sonar of all frequencies to find the target subs.
as for the 'no live fire' thats hogwash, people who live along the coast in the area heard explosions (probably due to a mine based excersize or large caliber guns firing)
the navy originally denied even being in the area at all, so can you trust them on any other point?
"no we werent there, oh maybe we were but we didnt fire anything honest.... well maybe just a few rounds.... and a mine or two but those dont really count right?"
btw you need to do a bit more research before you put the word 'fact' in the title of a facetious column, active sonar of both low and high frequency has been shown to damage cetetian hearing, causing massive damage to their inner ears (simple google search would have provided you info on that) and besides do you really believe that sonar has stayed the same since the 30's? seriously like it hasnt increased in power and changed in frequency multiple times? catch a grip.
i like my tuna sarnies as much as the next guy and dont really care that flipper gets stiffed for me to eat a tastey sandwich (dolphins are evil little buggers regardless of their good pr - watch vids of them torturing porpoise and youll be glad they beached) but i disagree with people pushing their own biased belief as fact.
mines the one with the objective reality