Initially "Boxer" was pressed into service to defend Portland harbour. After the war she went on to sail as a merchantman for several years. Her first voyage was in April 1815. Under Captain William McLellan, Jr. (1776–1844), she sailed to Havana, New York, Cadiz, Gibraltar, Marseilles, and back to New York before returning to Portland in early 1816. Subsequent shorter cruises under McLellan, Hall, or William Merrill took her along the coast, or to the West Indies. Around 1818 Merrill sold "Boxer" to a Portuguese firm that used her as a mail packet between Portuguese Cape Verde and Lisbon. Merrill reported that in 1825 he passed "Boxer" leaving Praia at dusk as he entered the harbour on his vessel "John". It is suggested that "Boxer" was finally lost on the coast of Brazil.