Three years later, the Rhode Island General Assembly appointed Whipple commodore of two ships fitted for the defense of the colony's trade. On June 15, 1775, (the day the sea captain received his commission), Whipple led his men to capture the tender to frigate HMS Rose. After cruising in the vicinity of Narragansett Bay, he headed south to Bermuda to procure gunpowder for use by the colony. On the return voyage, Whipple transported naval recruits to Philadelphia. Upon her arrival there, his ship, Katy, was taken over by agents of the Continental Congress and was fitted out as sloop-of-war Providence.