HMS Constant was an Archer–class gun-brig of the Royal Navy, launched in 1801 for service against the French during the French Revolutionary and Napoleonic Wars. She was variously stationed in English home waters, the Baltic, the Caribbean, and off the coast of Spain, and was responsible for the capture of at least seven enemy vessels during her fifteen years at sea. The Royal Navy sold Constant at Chatham Dockyard in 1816.

Surveillante entered service as a 40-gun Virginie-class frigate of the French Navy. She was surrendered to the British in 1803, after which she served in the Royal Navy, classed under the British system as a 38-gun vessel, until 1814 when she was decommissioned. HMS Surveillante had a long and active career under two successful and distinguished commanders, from the Baltic to the northwestern coasts of France, Spain and Portugal, and was present at the Battle of Copenhagen (1807) and throughout the Peninsula War. Her record as a taker of prizes is notable for its success, particularly towards the end of her career.