The intro by Monsarrat contains the statement "No one save a power maniac, a sadist, or a nautical romantic can hold any brief for submarine warfare. It is a repellent form of human behavior".How true. In recent years it has become popular to idolise the role of a U-Boat Captain. Whilst taking nothing from them from life within the confines of an 'iron coffin', it was one thing to match wits with a surface warship and a very definite other, to sink defenseless merchant ships without warning. That did not take courage or bravery to accomplish. This is from one who was on the receiving end of a tin fish.