A cracking wartime adventure about a submarine tasked with tracking down and destroying the new Nazi battleship "Brandenburg". The added authenticity of this being actually made during the war is hard to overstate; there is a palpable tension as Eric Portman and John Mills take centre stage in this - admittedly "flag waving" production. Featuring a daring raid on a fuel dump, a tense cat-and-mouse chase, and giving more than a nod to the concomitant problems faced by the families left behind ashore; this is a taut and convincing tale of underwater seamanship.