On the outbound leg of her eighth voyage she transported convicts to Port Jackson, New South Wales.

[1] Duke of Portland, Thomas Pittman, master, Daniel Bennett, owner, left Britain on 20 March 1797 on her first whaling voyage.

[5] Captain Ransom Jones was master on Duke of Portland's third whaling voyage.

[2] At the time of receiving the letter, Jones and Duke of Portland was already on her way on her fourth whaling voyage.

[2] However, it was Captain John Clarke Spence (or Spencer) who sailed Duke of Portland on her sixth whaling voyage.

[5] On his return Captain John Clarke Spence received a letter of marque on 22 July 1805.

[5] Duke of Portland sailed on 13 December 1806,[5] or 19 February 1807 under the command of Captain John Spence, and in company with Lively and Ranger.

[5] On 14 July 1808,[5] or 3 August 1808, Duke of Portland, Spence, master, sailed again from England, and arrived at Port Jackson again on 24 January 1809.

[8] Apparently, she first visited Guadalupe Island, off the California coast and took on a cargo of seal oil and skins.

[10] Duke of Portland is last listed in the Register of Shipping in 1811 with J. Spence, master, D. Bennet, owner, and London-South Seas as trade.