The general outline of the Battle of the Atlantic is well-enough known. In the first years of the war, Nazi Germany put hundreds of U-boats to sea, not only threatening the lifeline between North America and the island nation of England, but actually threatening to sever it by sinking more ships than the Allies of the period could build.
But this documentary is different from any of the others I've seen. It sketches in the overall narrative but it's also extraordinarily detailed and balanced in its presentation. We get to the know the suffering of the U-boat's victims but the U-boat crews and their tribulations are also dealt with. It's horrifying to be aboard a torpedoed tanker that's in flames. It's also horrible to be a crew member of an iron tube that is slowly being crushed by the hammering of depth charges. Death is virtually inescapable.
The usual statistics are presented -- the increase in the number of Liberty ships built in America and so forth. Those Liberty ships, by the way, were truly pieces of work. At full speed, beating against a headwind, they moved at the same rate as a man walking. And they were assembled in American shipyard from three prefabricated chunks of hull, which could split apart in a rough sea.
From 1939, when Germany entered the war with some 40 U-boats, until 1943, it was what the submariners called "the happy time." They could sail anywhere and do anything, and in the central Atlantic, they could do it without fear of attack from the air. They sometimes stopped and distributed food and water to the survivors and gave them the course to the nearest land.
During one large-scale rescue mission, an American bomber attacked and blew up some of the lifeboats being towed, despite the red cross flag draped across the U-boats anti-aircraft guns. Thereafter, the head of the German Navy, Admiral Dönitz ordered an end to rescues. Hitler wanted to go farther and have the boats strafe and kill the survivors but Dönitz refused. The crews themselves would have objected because they were considered an élite force that followed international law and the law of the sea.
The numbers finally caught up with Dönitz and his U-boats. There were too many Allied ships and escorts; there were now escort carriers providing air cover, and new technology like radar and sonic torpedoes. Going to sea in a submarine after May, 1943, was suicide. One observer compares it, aptly, to the Kamikazes. Thirty-two thousand German submariners in World War II were killed or captured -- out of a total force of forty thousand.
I don't recall seeing a better, more concise, and yet moving story of the war against the U-boats. I recommend it highly.