Fifteen years later she was briefly refitted as a receiving ship for press ganged sailors brought into Sheerness Dockyard, before being re-registered in August 1779 as the fireship Comet.

[1] Diligence was one of three vessels built to a 1755 design by Surveyor of the Navy William Bately, and collectively known as Alderney-class sloops in recognition of HMS Alderney which was the first to be formally contracted for construction.

This was Bately's first experience with vessel design, for which he substantially borrowed from the shape and dimensions of George II's yacht HMY Royal Caroline, built in 1750 by Master Shipwright John Hollond.

[2] Bately then added to Hollond's hull design by lengthening the "fore-rake" – the area of the bow that extended beyond the keel – in order to improve the sloop's stability in heavy swell.

[1] As fitted out for Royal Navy service she was lightly armed with 10 four-pounder cannons ranged along her upper deck, accompanied by 12 1⁄2-pounder swivel guns for anti-personnel use.