[4] Ledson was educated at Inangahua College and Christchurch Boys' High School, and joined the Royal New Zealand Navy as a cadet midshipman in January 1967.
Between January and June 1984 he attended the Royal Australian Naval Staff College in Sydney.
In November 1990 he was attached to Blohm & Voss, in Hamburg for eighteen months for duties with the ANZAC Ship project.
[citation needed] In February 1998 he was posted as Captain Fleet Support and was promoted Deputy Chief of Naval Staff, with the rank of commodore, in April 2000.
[citation needed] In the 2000 Queen's Birthday Honours, Ledson was appointed an Officer of the New Zealand Order of Merit.