Captain Maurice Usherwood, who died on September the 8th 2011 aged 99, demonstrated Asdic (a type of sonar) to Winston Churchill and was decorated after the relief of Corfu.

He became an anti-submarine specialist and in 1938 was in the destroyer Walpole when it was part of a secret demonstration for the First Sea Lord, Lord Chatfield, and Winston Churchill (then in the political wilderness, though being briefed by insiders). The exercise was to demonstrate the capabilities of modern sonar, known as Asdic.

Usherwood laid on an impressive display of detecting and attacking a “submarine” off Portland. Usherwood was not sure that Churchill fully understood the significance of the echoes of the Asdic “pings”, but the demonstration was such a success that some historians later suggested that it led to complacency about the U-boat threat. Churchill seemed to suggest as much in The Gathering Storm: “The faithful effort has relieved us of our great danger ... I had never imagined that I should hear one of those creatures asking to be destroyed.”

Usherwood, reflecting on it 50 years later, recalled that the conditions had been ideal, and that the success of his Asdic operators that day had amazed even him. He had been asked to demonstrate the capabilities of Asdic, not its limitations, and that was what he had done.

Usherwood was the naval commander of Operation Mercerised, a joint force which in October 1944 liberated the Greek island. Nos 2 (Army) and 40 (Royal Marine) Commando, under Brigadier Tom Churchill, had landed on the hilly Albanian coast north of Corfu; they needed to capture the port of Sarande in order to bring in reinforcements and stores, but were left stranded by heavy opposition and poor weather.

Usherwood was sent to see what he could do. After landing on a narrow gap in the tall cliffs, he went ashore to liaise with Churchill. Together they organised resupply of the commandos, and planned a surprise attack on Sarande, for which Usherwood brought up reinforcements, including more landing craft and two destroyers, Wilton and Belvoir. Meanwhile, the Assyrian Parachute Company (which had been raised in Iraq) was landed to outflank the German defences. After a bombardment by Usherwood’s destroyers, Sarande fell on October 9. Two days later Churchill and Usherwood decided on an advance to Corfu, which they found weakly defended.

They were greeted by an ecstatic Greek population and by two clerics, who from the colour of their beards became known as the black and white bishops, who seemed to be in charge. Urged on by the priests, a victory parade was held on October 14, led by Usherwood’s sailors. The march past was almost spoiled when Greek girls rushed forward to strew the road with long-stemmed roses, which caused havoc as an impromptu Greek band leading the parade was marching barefoot, and accordingly broke up in disarray. Usherwood was awarded a DSC.

His father retired to Ipswich and Maurice settled there upon his retirement in 1964 becoming heavily involved on the Old Peoples Welfare Committee the forerunner of Age Concern and the Citizens Advice Bureau in Ipswich as well as being vice president of the soldiers, sailors and airmen’s families association SSAFA. In October 1994 he was awarded an OBE for his charity work.