The Malta Force submarines had the vital task of interrupting German and Italian convoys crossing the Mediterranean to resupply Rommel and his Army in North Africa. The outcome of the Desert War depended on this. Operations from the beleaguered island were hazardous both at sea and in port. The Naval Base was under constant air attack. Due to the courage and tenacity of the crews by the time the Malta-based submarines were at full strength a staggering 50% of Axis shipping bound for Africa failed to arrive at its destination. The submarines sank some 75 enemy vessels totalling 400,000 tons. Periscope Patrol picks out the highlights of their actions and sets them against the bombed-out background of Malta, the island awarded the George Cross for its single handed stand. This is a hugely readable and informative account of submarine warfare at its toughest and roughest.