The action of 2 September 1781 was a minor naval engagement fought off Cape Ann during the American War of Independence; HMS Chatham captured the French frigate Magicienne after a fight of a few hours.

[3] On 2 September, the British fifty gun fourth rate HMS Chatham under Captain Andrew Snape Douglas was cruising off Cape Ann near Boston harbour and spotted the French frigate Magicienne, escorting a merchantman.

[4] She was a thirty six gun 800 ton frigate that was serving in comte d'Orvilliers fleet and was commanded by Captain Janvre de la Bouchetière[1] with 280 men.

[8] Sagittaire, Astrée and Hermione, which were anchored at Boston, scrambled in an attempt to support Magicienne, but they failed to arrive on time, and Chatham could escape with her prize.

[4] Subsequently, the action thwarted a planned French assault on British ships in the Saint John River.