3), later renamed A-2, was one of seven Plunger-class submarines built for the United States Navy (USN) in the first decade of the 20th century.

Adder was laid down on 3 October 1900 at the Crescent Shipyard, Elizabethport, New Jersey, by Lewis Nixon, a subcontractor for the Holland Torpedo Boat Company, New York City; launched on 22 July 1901; sponsored by Mrs. Jane S. Wainwright, wife of Rear Admiral Richard Wainwright.

Adder was commissioned on 12 January 1903 at the Holland Torpedo Boat Station at New Suffolk, New York with Ensign Frank L. Pinney in command.

Placed out of commission on 26 July 1909, Adder was loaded onto the collier Caesar, and was transported to the Philippines, arriving on 1 October.

Over almost a decade, the submarine torpedo boat operated from Cavite and Olongapo, principally in training and experimental work.