Viper was on her first cruise in 1776 under her captain, Commander Benjamin Wormell (or Wormwell), when the British captured her.

The notice in the London Gazette, under the heading "By the Perseus", simply states: "Viper, B. Wornwell, Master, Martin and Co. Owners; from Boston, on a Cruize; fitted as a Privateer.

On 7 May 1778, Viper was part of a squadron that accompanied some gallies, barges and troops up the Delaware River from Philadelphia to Trenton.

Over a three-day period they burned 44 American vessels and captured a battery of six guns, all without suffering a single casualty.

[6] In 1779, Lieutenant Monins Hollingbery (or Hollingberry) replaced Packenham, but then transferred to Royal George.