Arthur Henry Rostron was the captain of Carpathia, the ship that came to the rescue of the distressed Titanic, defying the ship's limitations to reach the site and rescue 706 survivors. Following the rescue, Rostron became the most celebrated and decorated master mariner of his generation, winning, among other awards, a Congressional Gold Medal. Following the Titanic rescue, Rostron served throughout the First World War, captaining the Cunard liner Mauretania, first as a hospital ship and then as a troop ship.

Using original documents, newspapers, contemporary publications, and secondary sources, Captain of the Carpathia considers Rostron's life and seafaring in his era, from his early days rounding Cape Horn in sail to his retirement as commodore of the Cunard Line. The book explores Rostron's seafaring life, using it as a platform to discuss the wider history in which he was involved, including the evolution of the transatlantic passenger trade and some of the celebrated ships on which he served and commanded.