The year 2001 records the 100th anniversary of the foundation of the Submarine Service, and Antony Preston presents a day-by-day account of life in the service. In 1901, Holland One, the Royal Navy's first submarine, fitted with a single torpedo tube, was born at Vickers-Armstrong amidst great controversy, in an era when the submarine was regarded as the weapon of the weaker power. Submarines quickly became established in the fleet but were still regarded with some disdain. They still remained relatively primitive craft - three caged white mice were the only warning of dangerous petrol exhaust gases. The Royal Navy entered World War One with 100 submarines and five Victoria Crosses were won. Between the wars, overseas squadrons were established maintained British presence around the globe, a significant number of new classes of submarine were built to fulfil the task.