Launched in 1744, the ship sailed to North America in June, bringing news of the start of King George's War and capturing two merchant vessels.

Returning to Charleston in the sloop Pelham, the Irish members of Swallow's crew planned a mutiny on 21 January 1745 to take the ship to St. Augustine, Florida, but were arrested before they could do so.

While they were established as 10-gun vessels, the sloops were built with 7 gun ports on each side, providing them with the capability to hold a larger armament.

[3] The sloops were the largest single-design class of ship in the Royal Navy when they were procured, and continued to be so until the advent of the Swan-class ship-sloop in the 1770s.

[3] With the construction of all ships of the class contracted out to civilian shipyards, Swallow was ordered to John Buxton of The Pageants on 7 July 1743.

Swallow and her sister HMS Merlin were fitted with a platform in their hold which severely decreased the depth of it; this feature was discontinued in most of their successors.

[8] Swallow was then sent to North America, carrying a letter from Thomas Pelham-Holles, 1st Duke of Newcastle to William Shirley, the governor of the Province of Massachusetts Bay, announcing the start of King George's War.

Swallow arrived in Boston on 2 June; her news placed the colony on a war footing, with Shirley forwarding the message to his fellow governors.

[1] In late December the ship was tasked with sailing from Charleston to New Providence, returning two brass mortars and their ammunition which had been lent to Major-General James Oglethorpe for the Siege of St.

[1][12] Making her way between Great Sale Key and the Abaco Islands, the ocean current moved Swallow further to the east than her crew had calculated.

[16] Jelfe's career was not negatively affected by the wreck; he was promoted to captain on 14 April 1746 and served in command of four other warships before his death in 1765.