Germany entered World War One engaged in a heated naval race with Great Britain. The introduction of the Dreadnought by Great Britain in 1906 made Germany focus almost completely on the creation of a battleship fleet, instead of her fledgling U-Boat program. This paper follows the course of the dreadnought race, the early advancement of the U-Boat, the history of Handelskrieg, and three situations in which Germany was poised to harm either the British battle fleet or take the island nation completely out of the war with the destruction of its mercantile shipping. This paper looks at the important events of the U-Boat campaigns against Great Britain during World War One and analyzes just how close Germany came to victory on numerous occasions, relying solely on the U-boat