Submarine warfare

Naval warfare is divided into three operational areas: surface warfare, air warfare and submarine warfare. Each area is comprised of specialized platforms and strategies used to exploit tactical advantages unique and inherent to that area.

Modern submarine warfare is comprised primarily of submarines and other underwater devices, technologies, and strategies for their use in cooperation with other operational areas to complete tactical objectives.

For most of history, submarine warfare has been restricted to the deployment of mines and other unmanned static devices intended to deny use of naval assets on bodies of water. Ancient examples of this kind of warfare include placement of sharpened sticks in shallow water so that soldiers who waded out into the water, or jumped from boats into the water, would be injured. Modern history provides numerous examples of combatants placing obstacles at harbor mouths or in rivers to impede the passage of shipping.

Explosive mines were developed in the 18th century in naval applications, but their use was limited by the lack of adequate fusing technology.

The first attempted submarine attack in wartime was by Sgt. Ezra Lee of the U.S. Continental Army in David Bushnell's hand-cranked egg-like submersible, Turtle, in New York harbor during the Revolutionary War. The first successful submarine attack in wartime was by Confederate submarine CSS H.L. Hunley (named for her designer, Horace Hunley), which sank frigate USS Housatonic. Not until the end of the 19th century had technology advanced sufficiently (batteries and diesel engines) to permit the production of submarines that could actually influence a war, with the appearance of John P. Holland's A-1.

Submarines were the weapon of the guerre de course (commerce war), which weaker nations were forced into by stronger naval rivals. It is contrary to the doctrine of Alfred Thayer Mahan, which calls for "decisive battle" against the enemy's fleet to ensure commerce protection. During World War Two, Germany and the United States relied on guerre de course, which nearly defeated Britain and ruined Japan's economy.