During the French Revolutionary Wars she served as a hired armed ship, primarily escorting convoys but also seeing some action.

[4] Captain Thomas Walker sailed Chapman from Portsmouth on 13 March 1781, bound for Madras and Bengal.

[2] Chapman was part of a convoy of Indiamen accompanying a British squadron under Commodore George Johnstone.

[2] One day later, Chapman was present at the Battle of Porto Praya, when a French squadron under the Bailli de Suffren attacked Johnstone.

The French did capture the Indiamen Hinchinbrooke (recaptured the next day), and Fortitude, and the victualer Edward, and gained a strategic victory, because Suffren beat Johnstone to the Cape and reinforced the Dutch garrison before continuing on his journey to the Île de France (now Mauritius).

Johnstone went on to capture five Dutch East Indiamen and destroy a sixth at the battle of Saldanha Bay on 21 July.

Homeward bound, she reached St Helena on 29 October and the Bristol Channel on 7 February 1783, before arriving at The Downs on 9 March.

[2] Chapman served the Royal Navy as a hired armed ship between 29 April 1793 and 12 November 1801.

On 21 June, Chapman joined a squadron of frigates under Sir Thomas Williams assisting troops under General Lake fighting Irish rebels near Wexford.

The wind picked up and on 2 February, one of the convoy, the Helen and Mary, Thomas, master, lost her bowsprit, foremast, and main-top mast.

[15] Following the resumption of war with France in early 1803, concern developed in Britain about Napoleon's planned invasion of the United Kingdom.

The British East India Company in November voted to underwrite 10,000 tons (bm) of armed transports to protect Great Britain's coasts.

The vessels were: Albion, Anacreon, Atlas, Aurora, Chapman, Diadem, Duckenfield, Helder, Indefatigable, Lord Forbes, Lord Nelson, Norfolk, Paragon, Perseus, Robert, Sir Alexander Mitchell, Suffolk, and Triton.

[16] Circa 21 November 1803 Chapman, of 555 tons (bm) and 24 guns, was appointed to the Leith Station.

[17] Captain John Constable left Portsmouth on 10 March 1812, bound for Bombay, Madras, and Bengal.

The convoy also included Roxburgh Castle, which was carrying military equipment to the Cape of Good Hope.

[20] Chapman, under the command of John Drake and surgeon Alexander Dewar, departed Cork, Ireland on 14 March 1817, arrived in Sydney on 20 July 1817.

[22] An investigation at Port Jackson by Judge-Advocate Wylde, Principal Surgeon and Superintendent of Police D'Arcy Wentworth, and Governor Macquarie's secretary, J.T.

The key parties from Chapman, Drake, Dewar, and Lieutenant Christopher Busteed of the 69th Regiment of Foot (the commander of the army detachment), and several soldiers, came to trial at the Admiralty Sessions of the Old Bailey on 11 January 1819.

[25] Chapman, again under Milbank's command, but with surgeon J. Hughes, departed London on 10 April 1826 and arrived in Hobart Town on 7 October.

[28] Lloyd's List reported that Chapman had arrived at St Helena from Batavia after severe gales.

A letter from James Chubb Tolman to his son William, written from London on 29 September 1853, says that "... Chapman bound for Hobart Town ... sailed from Gravesend on the 13th last".