During the Peace of Amiens, Upton was promoted to Post Captain and in December 1804, following the restoration of war with France in May 1803, was given command of HMS Lapwing.

At the age of eleven, he joined the Royal Navy as servant to captain Richard Kempenfelt, aboard HMS Alexander.

He passed his lieutenant's examination in 1790 but was unable to find employment within the service, and between 1791 - 1794 worked on merchant ships travelling to and from the Eastern World.

[1] She had been fitted as a fireship was sent to the Baltic with a large force, under Admiral Sir Hyde Parker, to disrupt the league of armed neutrality.

[2] Zephyr was in a squadron of sloops and frigates, under the command of Edward Riou, that attacked the Danish vessels near the harbour mouth.

[1] Despite the marriage of his parents a year after his birth, Upton's illegitimacy could not be revoked and he was deprived of any legal claim on the family estate.

Upton did not receive the family barony though, which passed to his brother John, the eldest surviving of the couple's three legitimate offspring.

[1] Upton was married in 1805, at St Pancras Old Church, London, to Elizabeth Walton, whose father was a wealthy American merchant.