He designed over 2400 vessels, including yachts that won Admiral's Cup, Cowes Week, and the Fastnet Race.
After he left de Havilland, he started as a boat designer firstly from his home in Enfield and then at his office which he established in Burnham-on-Crouch.
[3] In 1948 the Burnham boatyard of RH Prior & Son started work on his first design specifically for ocean racing.
[3] In 1956 he was commissioned by the London Rowing Club for a vessel (Casamajor) which had to be fast but with minimal wash for use as a coaching boat for their racing eights on the River Thames.
In the 1950s and 60s Buchanan was designing steel-built yachts where the basic steelwork was completed in Dutch yards, with the fitting-out being done in England.