Fast attack craft

Fast attack craft (FAC) are naval vessels that have been termed "eggshells with sledgehammers". They are not seaworthy for "blue ocean" operations, but can be a powerful part of a coastal defense force. The first versions appeared around the beginning of the twentieth century, and their "sledgehammers" were torpedoes that could cripple or sink a battleship — if the torpedo boat could survive to get into range. Destroyers were originally called "torpedo boat destroyers", as vessels large enough to accompany a battle force crossing oceans, but nimble enough to fight torpedo boats.

The concept evolved, with some FAC armed with guns alone, but were threats to transports and landing craft. By the end of the Second World War, however, surface-launched anti-ship torpedoes were obsolescent. Submarines still used torpedoes as their primary weapons, but their torpedoes were larger and more capable than those on FAC. In a turnabout, destroyers and cruisers were the more effective anti-surface warfare torpedo launchers in WWII, especially Japanese vessels armed with the Type 93 "Long Lance" torpedo. The U.S., however, used both FAC and destroyer launched torpedoes at the Battle of Surigao Strait; the PT boat FACs were more of a nuisance, while the destroyers were deadly.

With the introduction of the Soviet Osa-class and Komar-class, FACs took a quantum jump in lethality, when they were equipped with anti-shipping missiles. While Egyptian Osas have been credited with the first sinking of a vessel by a ship-launched missile, the Israeli destroyer Eilat in 1967, the SS-N-2 STYX missiles may have come from Komars.