Guybon Chesney Castell Damant

Damant was born on the Isle of Wight to Henry Castell Damant and Mary née Wilson. His father was a solicitor and the family was of upper class origins, dating back to ancestors in the former county of Alost (now Alst, in present-day Belgium) including Pietr Damant, Bishop of Ghent, whose tomb can be found there in St Bravos Cathedral. Damant attended a boarding school called the Grange upon the Isle of Wight and later became a naval cadet aboard HMS Britannia. He married Eleanor May Brook on 23 July 1913 and had three children: Eleanor, Tommy, and Mary. Damant died on 29 June 1963 of colon cancer.

After becoming a naval cadet in 1896 Damant served on a variety of stations before joining HMS Excellent with the intent of becoming a gunnery officer in 1905. During his training, he was given a basic course in diving since gunnery officers were placed in charge of the divers. Being an amateur natural scientist he was fascinated by the underwater world and devoted his career to diving. In 1906 he met John Scott Haldane who was commissioned by the Admiralty to find a way to prevent decompression sickness. Damant volunteered and was allowed to join Haldane as a researcher and experimental diver. This research led to the invention of staged decompression, which is still in use today. Damant as an experimental diver, achieved a world record in deep diving on 31 August 1906 while testing these decompression methods by achieving 210 feet in Loch Striven. Haldane, Damant, and Arthur Edwin Boycott co-authored a paper that disseminated the new knowledge.[1][2]

Damant was named inspector of diving in 1907 and worked on the salvage of several wrecks including HMS Gladiator (1908) and HMS Blackwater (1909). He retired from the navy in 1911 as a Lieutenant Commander.[2]

At the outbreak of World War I, Damant was recalled from the retired list. He served at HMS Excellent as a staff officer until late January 1917 when he was ordered by the Admiralty to recover the forty-four tons of gold bullion that sunk with the Laurentic off Lough Swilly on 25 January 1917. Using the mooring lighter, Volunteer, he and a crew of divers were successful at first and recovered three boxes of the gold. Then late winter gales drove them off the site for a couple of weeks. When they returned, the found the Laurentic crushed like an accordion. Divers, who had been working inside the wreck, were now forced to excavate vertically until they came in touch with the gold again in June and continued salvage operations. By the time salvage was called off in September, Damant and his team had recovered 542 bars out of a total of 3,211 that had gone down with the ship.[3]

In 1918, Damant was reassigned under the Naval Intelligence Division headed by Rear Admiral William Reginald Hall to lead a team of covert divers to enter and remove intelligence materials from freshly sunken U-boats. The work took place mostly in the English Channel but took them as far afield as Scapa Flow. They dove upon at least fifteen different wrecks of which approximately seven provided valuable intelligence material. Damant's team, which later entered into popular imagination as the so-called "Tin-Openers," materially contributed to the war effort. They were diving right until Armistice Day. For this and his work on the Laurentic, Damant was inducted into the Order of the British Empire (military division).

After the war, Damant returned to the Laurentic salvage and continued to work on the project until 1924. He and his team were highly successful, recovering all but 25 bars of gold. In subsequent years, private salvage companies recovered another five, leaving twenty bars of gold still under the wreck. To date, the salvage is the largest recovery of sunken gold by weight in history.[2]

After the war, Damant was made a Commander of the Order of the British Empire (CBE) in the 1924 Birthday Honours and promoted to Captain on the retired list. He retired to Cowes on the Isle of Wight and continued to consult on deep sea diving and salvage matters until his death in 1963.[2]

• Decompression (diving) – The reduction of ambient pressure on underwater divers after hyperbaric exposure and the elimination of dissolved gases from the diver's tissues
• Laurentic – British ocean liner sunk by mines in 1917