| CHAPTER | PAGE |
| I. | The Task of the Allied Navies | [17] |
| II. | The New Navy—Training an Anti-Submarine Force | [36] |
| III. | A Naval University in Time of War | [47] |
| IV. | The New Fleets in Being | [50] |
| V. | The Hydrophone and the Depth Charge | [70] |
| VI. | Some Curious Weapons of Anti-Submarine Warfare | [85] |
| VII. | Mystery Ships | [96] |
| VIII. | A Typical War Base | [102] |
| IX. | The Convoy System | [116] |
| X. | The Mysteries of Submarine Hunting Explained | [126] |
| XI. | The Mysteries of German Mine-Laying Explained | [143] |
| XII. | The Mysteries of Minesweeping Explained | [157] |
| XIII. | The Mine Barrage | [179] |
| XIV. | Off to the Zones of War | [187] |
| XV. | A Memorable Christmas | [192] |
| XVI. | The Derelict | [202] |
| XVII. | Mined-in | [209] |
| XVIII. | The Casualty | [220] |
| XIX. | How H.M. Trawler No. 6 Lost Her Refit | [226] |
| XX. | The Raider | [233] |
| XXI. | The S.O.S. | [238] |
| XXII. | In the Shadow of a Big Sea Fight | [248] |
| XXIII. | A Night Attack | [258] |
| XXIV. | Mysteries of the Great Sea Wastes | [264] |
| XXV. | From out the Clouds and the Under-seas | [273] |
| XXVI. | On the Sea Flank of the Allied Armies | [286] |
| | Index | [301] |