The USS Porpoise (SS-7), later designated A-6, was a Plunger-class submarine built for the United States Navy in the early 20th century. Laid down on December 13, 1900, at the Crescent Shipyard in Elizabethport, New Jersey, and launched on September 23, 1901, she was commissioned on September 19, 1903. This class represented an improved, enlarged version of the Holland submarine, featuring a length of 63 feet 10 inches (19.5 meters), a beam of 11 feet 11 inches (3.6 meters), and a mean draft of 10 feet 7 inches (3.2 meters). She displaced approximately 107 long tons on the surface and 123 long tons when submerged. Constructed primarily for experimental and training purposes, USS Porpoise had a crew complement of one officer and six enlisted men. Her propulsion system consisted of a single 180-horsepower gasoline engine for surface running and a 70-horsepower electric motor for submerged operations, allowing her to reach speeds of 8 knots on the surface and 7 knots underwater. She was armed with a single 18-inch torpedo tube in the bow, capable of carrying four reloads for a total of five torpedoes, and could dive to depths of up to 150 feet. Initially assigned to the Naval Torpedo Station at Newport, Rhode Island, USS Porpoise conducted experimental torpedo firing and later served with the First Torpedo Flotilla, including a period at the United States Naval Academy for instructional duties. In 1908, she was partially disassembled, transported as deck cargo via the collier Caesar through the Suez Canal, and arrived at Cavite, Philippines, where she was relaunch and recommissioned in November 1908. During her service in the Philippines, she participated in local patrols and harbor defense, notably during World War I, where she patrolled Manila Bay and convoyed vessels. One of her notable events occurred in April 1909 when Ensign Kenneth Whiting, a future pioneer of naval aviation, performed a daring experiment by passing through her torpedo tube underwater, a demonstration of the submarine's operational capabilities. USS Porpoise was decommissioned in December 1919, struck from the Naval Vessel Register in 1922, and ultimately used as a target ship. Her service exemplified early U.S. submarine development and operational experience in the Pacific theater.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.