Sea Skua

The Sea Skua is a British lightweight short-range air-to-surface missile (ASM) designed for use from helicopters against ships. It was primarily used by the Royal Navy on the Westland Lynx. Although the missile is intended for helicopter use, Kuwait employs it in a shore battery and on their Umm Al Maradem (Combattante BR-42) fast attack craft.

The Royal Navy withdrew the missile from active service in 2017. Its replacement, Sea Venom was considerably delayed with full operating capability was only anticipated in 2026.

Sea Skua traces its history, indirectly, to the immediate post-war era. Growing increasingly concerned about the threat of aircraft, especially after the introduction of glide bombs during the war, the Royal Navy was convinced that all ships required some form of surface-to-air missile (SAM) for defence. These systems tended to be relatively large, especially in the era before vertical launch, and it was difficult to mount both a useful SAM and a conventional gun on smaller ships.

This led to a series of experiments to produce a dual-use missile capable of both anti-air and anti-ship use, thereby removing the need for a gun. The original Navy guided-missile sets, Seaslug and Seacat, both had secondary anti-shipping roles. Seaslug was a large system and could only be carried by larger ships, while Seacat could be fitted to almost any ship but had a relatively short-range and small warhead suitable only for use against small boats. Neither filled the goal of replacing guns in any meaningful way.

In October 1960, the Navy launched a project with the goal of once again producing a single weapon that could fit on a 3,000 ton frigate and able to attack bombers, anti-shipping missiles, and other ships up to frigate size. This led to the Small-Ship Guided Weapon and ultimately to Sea Dart, which was tested in the anti-shipping role against a Brave-class patrol boat. It also ended up being too large for the smallest ships and was ultimately only fit for destroyers and larger ships. So, by the late 1960s, the role of a widely available dual-purpose weapon remained unfilled.

The sinking of the Eliat in 1967 led to the realization that small fast-attack boats carrying medium-range anti-shipping missiles were a serious immediate threat. A weapon was needed that could destroy any such craft before it could approach within the launching range of its missiles, which was longer-ranged than any light gun. Seacat did not have anywhere near the required range. Sea Dart did, but could not be fitted to the majority of RN ships. A new dedicated anti-shipping missile could fill the role, but it would have to be roughly the same size as those being aimed against it in order to reach the required range, which would make it take up too much room on a ship carrying many other weapons systems. This turn of events was the final nail in the idea of having a dual-purpose weapon.

The entire concept was reevaluated and led to the decision to launch a new weapon from helicopters. Long-range was not required, it only had to travel far enough to keep the helicopter out of range of any anti-aircraft weapons the boats might carry. Because the boats were small, these would be light weapons with limited range. The missile would be carried by the new Westland Lynx and its targets detected by a new lightweight radar, Seaspray. Its combat effectiveness was further improved by the addition of the Racal "Orange Crop" ECM suite, which allowed the helicopter to track the boats who were using radar to attempt to approach their target ships, allowing the helicopters to approach without turning on their Seaspray until the last moment.

The British Aircraft Corporation (BAC) began development in May 1972. The British Government authorised its production in October 1975. At the time, the missile was known as CL.834. The first launches took place in November 1979 at the Aberporth Range in Cardigan Bay. Three missiles were launched from the ground and three by helicopters. Further tests were made and in July 1981, full-scale production was ordered of the new missile, now called "Sea Skua".