Short answers, pulled from the story.
The first submarine attack allegedly took place on the 8th of September 1776, when the American submersible Turtle attempted to strike the British ship of the line HMS Eagle. The first confirmed sinking of an enemy ship by a submarine occurred on the 17th of February 1864, during the American Civil War.
Submarine warfare is one of four divisions of underwater warfare, alongside anti-submarine warfare, mine warfare, and mine countermeasures. It uses diesel and nuclear submarines armed with torpedoes, missiles, or nuclear weapons, plus advanced sensing equipment, against other submarines, ships, and land targets.
German U-boats sank more than 5,000 Allied ships during World War I. British and Allied submarines also operated across the Baltic, North, Mediterranean, and Black Seas, as well as the Atlantic Ocean.
The wolf pack tactic dispersed multiple U-boats across a convoy's likely path, with the first boat to sight it radioing its course, speed, and composition to German Naval Command. The rest of the pack then converged and attacked together on the surface at night, withdrawing at dawn.
Germany lost 793 U-boats in World War II, along with about 28,000 of its 41,000 submariners, a casualty rate near 70 percent. Allied losses to U-boats totaled almost 3,000 ships, including 175 warships and 2,825 merchantmen.
In March 2026, during Operation Epic Fury, the United States sank an Iranian frigate near Sri Lanka using a single MK 48 torpedo. It is one of the most recent uses of a submarine described in the record.