In addition to serving in the navy, he also became a director of the Danish Asia Company and ended his career as a vice admiral.

He married twice, In 1745 the manor house of Marienborg at Lyngby, just north of Copenhagen, was built for Olfert Fas Fischer.

As a cadet from the age of twelve, Fisker served under Andreas Rosenpalm in the Great Northern War until, in 1719 he was commissioned as a junior lieutenant.

[1] Following promotion to rear admiral in 1755 he became, in 1756, interim head of the Holmen dockyard and then, in 1758, commander of a squadron convoying large troop transports from Norway and Denmark to Eckenførde in Schleswig-Holstein.

This was granted in the sum of 300 Rigs dollar annually, and on the death of their mother twenty years later the six remaining unmarried daughters received a single supplementary payment of 30 Rdl.