From the earliest days of the Second World War, Hitler's U-Boats were unleashed with the mission of sinking as much Allied merchant tonnage as possible. From the sinking of the Glasgow-based ship Olivegrove by U-23, to the end of hostilities six years later officers and seamen of the Merchant Marine played a key role in winning the war by their blatant disregard of the risks from Axis forces. The most dangerous were the U-Boats working unseen but there were also surface raiders and aircraft. All too often the result was the loss of ship, cargo and, tragically, crew. But as described in this excellent book great gallantry against overwhelming odds brought rewards and surprising results. We learn of acts of both chivalry and brutal activity by the enemy. The actions described in this book are varied but always make for excellent reading.