Following the outbreak of the Fourth Anglo-Dutch War between Britain and the Dutch Republic Admiral George Rodney, acting under orders from London, captured the Dutch island of St Eustatius on 3 February 1781.
Mars under the command of Van Bijland was the only Dutch warship in the roadstead. Two British ships. Gibraltar and the Prince William shot at her without orders, for which their captains were reprimanded by Rodney. Mars was captured together with 5 other small ships of war and more 130 merchant vessels.
The Royal Navy commissioned Mars under Captain John Whitmore Chetwynd. He sailed her back to England as part of a fleet of prizes and other ships. She arrived at Portsmouth on 28 June 1781, and was paid off at Chatham in August. The Navy completed her survey there on 12 February 1782. It sold her on 25 March 1784 for £505.
Richard Bush purchased her and had Mars refitted by Adams as an East Indiaman.
Under the command of Captain William Farington (or Farrington), she left The Downs on 26 April 1786, bound for China as an "extra" ship for the EIC. Mars arrived at Whampoa on 11 December. She crossed the Second Bar on 22 March 1787, and was at Mew Bay (some two miles east of Tanjung Layar), by 11 May. She arrived at Mauritius on 15 June, and left on 4 August. By 21 September she was at St Helena, which she left on 2 October. Mars arrived at The Downs on 8 December, but was lost on the Margate Sands the next day. The pilot made an error that resulted in her stranding. The cost to the EIC of the loss of her cargo was £70,000.