"Shark" put to sea from Hampton Roads on 22 July 1839 for duty with the Pacific Squadron. She was the first United States man-of-war to pass through the Straits of Magellan from east to west, a feat accomplished on 13 December 1839 en route to Callao, Peru. During the next five years, she spent much of her time along the coast of Peru to protect American citizens and property during civil disturbances in that country. The Secretary of the Navy noted in 1841 that “all who witnessed the operations of the "Shark" were inspired with increased respect for the American flag.” She also made infrequent cruises northward to observe conditions in Panama and to receive mail.