The airbase is situated near two notable landmarks, on the south east side of Loch of Isbister, with Brough Head 3.25 miles (5 km) north west.

On 30 March 1944 initial plans were to make Twatt the only airfield suitable to aid the disembarkation of squadrons of the Home Fleet.

[3] During the 1970s it was proposed to merge with nearby RAF Skeabrae to create a large NATO base, but Iceland was chosen instead.

[4] There was an operational requirement that identified the need for airfields in Shetland, Orkney and Northern Scotland (SOM 358/40) during Spring 1940, with the site at Twatt being surveyed.

[4] It was situated between two roads on farmland, with Loch of Ibister to its north, and constructed by contractors, along with Royal Marines engineers.

700 Naval Air Squadron (700 NAS), which provided final training for catapult aircraft aircrew before they embarked on their assigned ships, remained at the airbase from June 1942 until disbanding during 1944.

It operated a number of different aircraft types, undertaking various tasks, supporting the Home Fleet at Scapa Flow.

All these types exercised the ships of the Home Fleets' and shore-based, anti-aircraft guns and also provide targets for radar practice and calibration.

It moved its HQ the short distance across Mainland, Orkney, to RNAS Twatt (HMS Tern) during June 1942 and at that point the squadron was equipped with sixty-three Supermarine Walrus amphibious biplanes.

[5] The training was broken down into an initial three weeks of aerodrome flying, consisting circuits and landings, dive-bombing, photography and anti-submarine warfare, at RNAS Donibristle (HMS Merlin), in Fife.

On 5 November 1941 it moved north to RAF Sumburgh after reports that Nazi Germany's Kriegsmarine Bismarck-class battleship Tirpitz was in the area.

It embarked back onto HMS Victorious for attacks on shipping in Vestfjorden[12] Following attacks on shipping around the Lofoten Islands, operating from HMS Victorious, a detachment of 832 Naval Air Squadron Fairey Albacore torpedo bombers stayed at RNAS Twatt between 20 and 23 September 1941.

During the following twelve months the squadron took part in several deployments on Victorious including escorting Arctic convoys to northern ports on the Soviet Union and anti-shipping strikes in the Bodø area of Norway.

On 22 July 1942 809 NAS embarked onto Victorious, for the final time from the Orkney airbase, before moving south to RNAS St Merryn (HMS Vulture), in Cornwall, England.

[15] 822 Naval Air Squadron, operating with Fairey Albacore torpedo bomber, moved from RNAS Machrihanish (HMS Landrail) on 27 September 1942.

It was working up when it left for RNAS Hatston, on its way to embark onto the Illustrious-class aircraft carrier HMS Formidable to support with the North African landings, on 21 October.

The carrier was assigned to Force H for Operation Torch, where two of 820 Naval Air Squadron Fairey Albacore torpedoed and sank the German submarine U-331.

[19] With Germany's unconditional surrender of its armed forces on Tuesday, 8 May 1945 and the disbandment of the catapult training unit, 700 NAS, the previous year, the airbase saw a lot less activity.

A couple of FAA squadrons passed through shortly after VE Day and the Fleet Requirements Unit remained at RNAS Twatt until July 1945.