Bristol Aerospace, which had recently introduced the ramjet-powered Bloodhound missile for the RAF, won the ensuing competition with another ramjet design.

Compared to Seaslug, Sea Dart was faster, had much greater range, and its semi-active radar homing guidance was much more accurate and allowed attacks against supersonic targets.

Some consideration was given to a high-performance gun system for these ships, the DACR (direct-action, close-range), but calculations showed it would be useless against future anti-ship missiles that would manoeuvre on the approach.

[4] In October 1960, the Navy launched the Small Ship Integrated Guided Weapon project to fill this need, SIGS for short.

A review by the Defence Research Policy Committee agreed with the Navy that the new design represented an entirely new class of weapon and that development should be undertaken immediately.

[5] Two systems were considered for the role, Bristol's CF.299 design using a ramjet with a small rocket booster launching it up to speed, and an adaptation of the Army's Sightline project, which would later emerge as Rapier.

A 1966 report estimated that CF.299 would have a two-shot kill probability (Pk) against an AS-2 Kipper missile of 0.8–0.9, whereas Seaslug II would manage only 0.35–0.55.

Additionally, because it flew faster than Seaslug, the total engagement time was shorter, and this meant the battery could salvo more rapidly.

They envisioned it being used with a new dedicated air-defence ship, controlled by a significantly more powerful radar which the British referred to as the Type 988 "Broomstick".

[5] Ultimately, the Dutch also chose Tartar for their missile component, leaving the Royal Navy as the Sea Dart's only initial user.

It is launched using a drop-off Chow solid-fuel booster that accelerates it to the supersonic speed necessary for the operation of the cruise motor, a Rolls-Royce /Bristol Siddeley kerosene-fuelled Odin ramjet.

It has a secondary capability against small surface vessels, tested against a Brave-class patrol boat, although in surface mode the warhead safety arming unit does not arm, and thus damage inflicted is restricted to the physical impact of the half-ton missile body and the unspent proportion of the 46 litres (10 imp gal; 12 US gal) of kerosene fuel.

Sea Dart was used during the Falklands War (1982) and is credited with seven confirmed kills (plus one British Westland Gazelle helicopter downed by friendly fire).

This was important because Argentine aircraft such as the Dassault Mirage III had better straight line performance than the British Aerospace Sea Harriers, which were unlikely to successfully intercept them.

The first Sea Dart engagement was against an Aérospatiale Puma, on 9 May 1982 near Stanley by HMS Coventry, with the loss of the three men aboard.

An unguided Sea Dart was launched in an effort to disrupt the attack but missed, and the destroyer was struck by two iron bombs and sank.

The same day a Dassault-Breguet Super Étendard strike fighter sought to attack the British carrier group with Exocet missiles, but instead struck the cargo ship MV Atlantic Conveyor.

Finally, on 13 June 1982, an English Electric Canberra flying at 12,000 metres (39,000 ft) en route to bomb British troops near Port Harriet House was destroyed by a Sea Dart fired from Cardiff.

Consequently, Argentine planes, opting to fly below the Type 965 radar ("sea skimming"), frequently dropped bombs which failed to explode.