On 24 March, 1800 a heavy gale hit Cape Town capsizing and sinking USS Essex's launch, the crew was saved with difficulty by her barge.

[1] From December 1802 she was commanded by Captain Samuel Mottley,[2] and was the flagship of Rear Admiral Sir James Saumarez from June 1803 for the next three years.

In January 1804 she was commanded by Captain Hugh Downman (as Mottley had returned to Britain aboard Leopard), and deployed to the Channel Islands and the North Sea.

In 1821 the survivors of the flotilla shared in the distribution of head-money arising from the capture of the American gun-boats and sundry bales of cotton.

On 7 July 1815, Diomede was ordered to become a provisions depot vessel at Sheerness, but upon inspection was found to be too decayed so was broken up in August 1815.