John Doggart was born in Scotland on 15 February 1951, the son of Hugh Black and Margaret Campbell Doggart (née Yeates). He joined the Royal Navy as a Cadet on 1 September 1969. He was promoted to Midshipman (E) on 1 September 1970 and was appointed to HMS NEPTUNE and promoted to Sub Lieutenant (E) on 1 September 1971. From 1972 to 1975, he was a student at the Royal Naval Engineering College, Manadon.

John Doggart was appointed to HMS DOLPHIN for the Submarine Course in 1977 and then served in HMS OPPORTUNE as the WEO (1978 to 1980), being promoted to Lieutenant (E) (WESM) on 1 August 1978.

He next served on the staff of The Captain, Weapons Trials, based at HMS VERNON in 1981 and 1982. He then served in HM Naval Base Clyde (1983 & 1984 NL) and was promoted to Lieutenant Commander (E) (WESM) on 1 August 1984. After a return to HMS DOLPHIN in 1985, he was appointed to HMS COURAGEOUS as the WEO (1986 to 1988 NL).

An appointment to HMS DEFIANCE (Fleet Maintenance Base) followed from 1989 to 1992. John Doggart is reported to have died in the Royal Naval Hospital at Stonehouse, Devonport on 25 November 1992, following illness. He was the husband of Jane Doggart, and is buried in the Rothesay New Cemetery on the Isle of Bute.