Denis Carey was a Flight Lieutenant in the Royal Air Force. According to his logbooks, Carey flew over eighty different types of aircraft. The seaplane test-site on the Isle of Grain was one of the principal sites out of which he flew. This facility was established in 1912 by Winston Churchill for the Royal Naval Air Service (which merged with the Royal Air Force in 1918). Following World War I, test-flying of seaplanes continued to be carried out at the Isle of Grain.