Professor Lucy Blue speaks to Professor Dave Parham from Bournemouth University who has been diving on the remains of 1944 Valentine Tank assemblage in Poole Bay. Made buoyant by the addition of a canvas skirt they proved essential in getting armoured support onto the beach during the historic D-Day landings.  Scheduled under the Ancient Monuments Act means they are protected by law. On a recent inspection the turret on one tank was found to have been pulled off.  There were no obvious clues as to the culprit, so the police were called in to help solve this crime.  Who did it? How can such sites be policed? Can you help solve this crime?  Learn more about the importance of these tanks that sank in bad weather during Exercise Smash in the run-up to this historic manoeuvre.