Piers was captain of the Canadian destroyer HMCS Restigouche from June 1941, during the battle to maintain the critical convoy routes to Britain. He was at the centre of a crisis in this battle. In October, 1942 Piers commanded escort group C4 which was to escort the slow convoy SC107, from Sydney, Nova Scotia to Liverpool. At the time, Canadian escort ships were regarded as inferior to their British equivalents and they were generally assigned to the slower, more vulnerable convoys. On this occasion, Restigouche was the only ship of Piers' group with working radar and direction finding equipment, both necessary to locate u-boats. In the circumstances, exacerbated by a failure to reroute the convoy away from the u-boats, it is unsurprising that the convoy, once found, would be severely mauled, losing 15 of its 42 ships. This level of losses was unsustainable and Admiral Sir Percy Noble, the then Commander-in-Chief, Western Approaches, insisted that Canadian escorts immediately be withdrawn for training or reassigned to less vulnerable routes. Although Piers received criticism for his group's performance, he had been aggressive in the convoy's defence. This was recognised by the award of the Distinguished Service Cross, some months later On September 26, 1943, Piers played a key role in an attempt by the Royal Canadian Navy and Canadian Army to trap a German submarine sent to pick up escaping prisoners of war at Pointe de Maisonnette, New Brunswick. The attempted escape was codenamed Operation Kiebitz by the German authorities. Only one prisoner, Wolfgang Heyda, made it from Bowmanville to Pointe de Maisonnette. Piers, after questioning him at the lighthouse, unmasked Heyda despite his initial denials. Recollecting the event after the war, Piers remarked, "I offered my regrets, but I had to return him to detention. I telephoned the RCMP. They came in a car and, a few moments later, I handed him over to them." While none of the POW's got away, the submarine sent to pick them up was able to escape, only to be sunk a few weeks later.
Post-war
Piers returned to the Royal Military College of Canada as Commandant in 1957. In 1967, Piers retired to his home in Chester, Nova Scotia, doing community work until 1977 when he was appointed Agent General of Nova Scotia in London. This appointment entailed the support abroad of Nova Scotia's interests. In this role, he promoted the province's use of tidal energy. In the following year, 1978, he was made a Freeman of the City of London. To Desmond's seven grandchildren, he was always referred to as Grandeb and will always be remembered as the one engaging in musicals and small plays with the grandchildren. He never gave up a chance to teach them how to play the harmonica, as it was one of his favourite hobbies. He was a true inspiration to everyone. Desmond "Debby" Piers died in Halifax, Nova Scotia on 1 November 2005. He had married Janet Macneill in 1941, the couple had had one stepdaughter Anne. On June 2, 2007 a memorial monument in recognition of Rear Admiral Desmond William Piers was placed outside his Chester home. It can be seen on Front Street, down by the ocean in Chester, Nova Scotia.
