A wartime account of the merchant fleet’s role during the Great War, describing mobilisation, the conversion of passenger liners into armed and hospital ships, and the steady movement of troops and materiel under escort. The narrative recounts encounters with enemy submarines, notable sinkings and survival episodes, and the everyday practices adopted at sea—camouflage, armament, convoy procedures and boat drills—alongside shore-based contributions such as factory and aeroplane work. Drawn from officers’, captains’, and crews’ recollections and contemporary photographs, the account emphasizes practical challenges, seamanship, and sacrifice as civilian vessels and their personnel sustained global logistics and evacuated or treated the wounded amid modern naval warfare.