She had barely begun her first cruise when she encountered the 44-gun ship HMS Assurance, Captain James Cumming.

[2] Captain John Melcombe assumed command in September, sailed to England on 29 October, and arrived in late November.

Melcombe arrived at the Admiralty on the Sunday evening before 27 November, bearing the news that General Cornwallis had surrendered at Yorktown.

She was armed with ten 6-pounder guns and had a crew of 50 men under the command of lieutenant de fregate LeFer.

Before he struck Le Fer threw overboard the dispatches, her logbook and papers, and eight guns.

[2] On 10 November 1784, Rattlesnake, Captain Melcombe, was escorting the merchantman Countess of Tuscany to Gibraltar when they encountered an Algerine naval squadron of nine ships under the command of an admiral.

The Algerine admiral pretended to believe that Rattlesnake was not a British warship and compelled both vessels to put into Algiers.