[2] At the age of 19, Douglas joined the Royal Navy, serving as captain's steward aboard HMS Wolverine.

He resigned from military service after 8 months, in September 1842, to become master of The Royalist and join his distant relation rajah James Brooke fighting pirates around Sarawak.

After this, he went back to England for five years and worked as a coastguard in Northumberland, he was in temporary command of HMRC Eagle c.1847-50; before returning to sea again.

[3] In December 1854, Douglas took up the post of naval officer and harbourmaster in Adelaide, South Australia, having arrived there on the merchant ship Bosphorus.

Outside of his maritime activities, Douglas spent time as a stipendary magistrate, a member of the Immigration Board and an Inspector of Distilleries.

[8] Attempts to introduce order into his administration were in vain, and he was made to resign in June at the request of commissioner Thomas Reynolds.

[9] In April 1874, the South Australian government gave Douglas a new task: to travel to Singapore to recruit gold miners for the Northern Territory.

Douglas remarried in January 1899 to Annie Maude (née McDonald), the daughter of the collector of customs for Sydney, Nova Scotia.