In that abyss of war there was romance sufficient for many generations of novelists and historians. Many were the epic fights, unimportant in themselves, but which need only a Kingsley or a Stevenson to make them famous for all time. So with the happenings to be described in this book, many of them historically unimportant compared with the epoch-making events of which they formed a decimal part, but told in plain words; just records of romance on England's sea frontier in the years 1914-1918. Although jealous of any encroachment on the space available for the description of guerrilla war at sea, there are many things which must first be said regarding the organisation and training of what may appropriately be termed the "New Navy," which took the sea to combat the submarine and the mine; also of the novel weapons devised amid the whirl of war for their use, protection and offensive power. Into this brief recital of the events leading to the real thing an endeavour will be made to infuse the life and local colour, which, however, would be more appropriate in a personal narrative than in a general description of anti-submarine warfare of to-day, but without which much that is essential could not be written without dire risk of tiring the reader before the first few chapters had been passed. The names of places and ships have necessarily been changed to avoid anything of a personal character, and all references to existing or dead officers and men have been rigidly excluded as objectionable and unnecessary in a book dealing entirely with events. Many of the incidents described--written while the events stood out in clear, mental perspective--could no doubt be duplicated and easily surpassed by many whose fortunes took them into zones of sea war during the historic years just past. If such is found to be the case, then the object of this book has been accomplished, for it sets out to tell, not of great epoch-making events, but of the organisation, men, ships, weapons and ordinary incidents of life in what, for lack of a better term, has been called the "New Navy"--a production of the World War. It may be that an apology is due for placing yet another war book before a war-weary public, but an effort has been made to make of the following chapters _a record of British maritime achievement_, more than a narrative of sea fighting, although to do this without introducing the human element, the arduous nature of the work, the monotony, the danger and, finally, the compensating moments of excitement would have been to falsify the account and belittle the achievement. There are many books available, full of exciting stories of sea and land war, but no other, so far as the Author knows, which describes in detail and in plain phraseology those important "little things"--liable to be overlooked amid the whirl of war--which go to make an anti-submarine personnel, fleet and base, together with an account of "how it was done." CONTENTS