Another periscopic prowl with the U-boats of the last World War will compete with the more capable coverage of Wolfgang Frank's The Sea Wolves (Rinehart) and David Woodward's The Secret (Norton)- both this year. In itself, it is a rather spotty chronology of individuals and individual incidents which combined to give this phase of naval activity its special, solitary heroism. Along with some notations on the cramped life aboard a U-boat, corkscrewing and pitching through dangerous waters, there is information on the objectives- offensive and defensive, on patrols, casualties, commanders (particularly the youthful ""Jochen""), on the development of new types of boats and the new counter-measures they faced. If this report, by a former German commander, is presumably authentic and accurate, its opening apostrophe is to be questioned- to record the bravery and endurance of a proud past ""at a time when Germany is struggling for survival as a nation"".