"The Dambusters" is the story featured in issue #8 of Action Man.
Action Man is competing in a triathlon, but Professor Gangrene tries to ambush him. Luckily, Action Man notices Gangrene and faces him. However, Gangrene was just diverting Action Man's attention while Dr X blew the dam. Action Man uses his kayak to go ahead the tidal wave that has formed, and goes towards the sluice gates in order to close them and stop the flow. He does it with seconds to spare, but then Dr X arrives in helicopter and tells he also rigged the sluice gates to explode. Action Man shoots the detonator control from Dr X's hand, and the defeated Dr X escapes.