An attack on the German battlecruiser Scharnhorst was attempted in September 1940, and on the squadron joined RAF Coastal Command in March 1941 for operations along the Dutch and French coasts.

The squadron joined HMS Dasher in February 1943 for Arctic convoy escort but faced heavy losses when the ship exploded in March 1943, during exercises in the Firth of Clyde.

Disbanded at RAF Perranporth in August 1944, it reformed at RNAS Lee-on-Solent in February 1945, as a torpedo bomber reconnaissance squadron on a light fleet carrier and stayed active until 1948.

816 Naval Air Squadron was established on 3 October 1939, aboard the Courageous-class battlecruiser, converted to an aircraft carrier, HMS Furious, equipped with nine Fairey Swordfish biplane torpedo bombers.

Notably, on 11 April, it executed the first airborne torpedo assault of the conflict, as eighteen aircraft from 816 and 818 Naval Air Squadrons targeted two Destroyers located in Trondheim Fjord.

On 4 June, nine Fairey Swordfish aircraft from the Torpedo, Bomber, and Reconnaissance Squadron arrived from RNAS Ford (HMS Peregrine), Sussex, for a week of operations, remaining until 11.

It was suspected that adverse weather conditions and limited visibility hindered their ability to locate the carrier, leading them to ditch the aircraft after exhausting their fuel supply.

[6] Following the re-equipping with six Fairey Swordfish II aircraft and subsequent working up, the squadron conducted night operations in the English Channel from September to December, under the auspices of RAF Coastal Command.

However, on 27 March 1943, the vessel suffered a catastrophic explosion in the Clyde due to an accident, resulting in significant casualties, including the loss of the squadron's Commanding Officer, Lieutenant R.C.B.

The Supermarine Seafire were replaced by Grumman Wildcat Mk IV fighter aircraft with in January 1944, after which the squadron was transferred to sister ship, HMS Chaser to serve in the Arctic convoys.

HMS Ocean made its return to the United Kingdom at the conclusion of June 1948, leading to the disbandment of 816 Naval Air Squadron at RNAS Lee-on-Solent on 1 July 1948.