The cover of the book 'Naval Power: A History of the Royal Navy from its Origins to the Present Day' by Jeremy Black. The cover features an illustration of a large sailing ship with multiple masts and sails, surrounded by smaller ships and boats on the water. In the background, there are mountains and a hazy sky. The title of the book is prominently displayed in large, bold letters at the top, with the author's name in smaller text at the bottom.