Despite the introduction of modern technology, Royal Navy ships and submarines still operate based on main announcements, known in the Royal Navy as pipes. Before the introduction of main announcements, a crew (or ship's party) would be alerted to impending ship activity using either a boatswain's call (a small pipe or whistle) or a bugle. Although these methods are still present and in use, pipe is now the name given to any verbal announcement made over a ship's main announcement in the Royal Navy. This book aims to translate their meanings, not only to make the seemingly incomprehensible understandable, but also to evoke often humorous anecdotes that provide insight into life at sea in the Royal Navy. Each pipe is provided with a brief description of its meaning, followed by a more detailed consideration of its significance to different members of the ship's crew.