Her design was that of a schooner. She was rigged with fore-and-aft sails on two masts. She was long and had a shallow of only . "Vigilant", launched in March 1791, it was probably the first cutter in the water. She was not, however, the first to enter into active service. Her first patrol was in December 1791. Her first master was Patrick Dennis, appointed on 6 October 1790. He also supervised the construction. Dennis served as master until his death on February 9, 1798.