The USS Reina Mercedes (IX-25) was originally built as the Spanish cruiser Reina Mercedes, an unprotected cruiser of the Spanish Navy. She was captured by the U.S. Navy in Cuba during the Spanish–American War in 1898. The vessel played a defensive role during the siege of Santiago harbor, serving as a key element of Spanish coastal defenses with her armament, including four 6.3-inch Hontoria guns and lighter weapons, positioned to guard the harbor's entrance. After the Spanish fleet was defeated, Reina Mercedes was sunk as a blockship in Santiago de Cuba harbor. Salvaged by the U.S. Navy in 1899, she was raised by Merritt-Chapman & Scott and towed to Norfolk Navy Yard for repairs, which revealed extensive damage—leaking heavily from hits received during her sinking. Subsequently, she was moved to Portsmouth Navy Yard for refitting, initially intended as a seagoing training ship. However, plans shifted, and by 1902 she was completed as a non-self-propelled receiving ship. From 1905, she was stationed at Newport, Rhode Island, serving as a receiving ship alongside USS Constellation until 1912, with brief visits to Boston and New York. In 1912, Reina Mercedes was relocated to Annapolis, Maryland, where she served as a station ship for the U.S. Naval Academy until 1957. She was designated an unclassified auxiliary vessel (hull number IX-25) in 1920. Throughout her service at Annapolis, she functioned primarily as quarters for enlisted personnel and as a headquarters for sailing activities, harbor control, and lookout operations. Notably, midshipmen serving disciplinary punishment would live aboard her until the practice was abolished in 1940. Reina Mercedes was unique in allowing dependents to live aboard, with her commanding officer's family quarters on board. She also briefly flew her former Spanish flag in 1920 as a gesture of friendship. In her later years, efforts by Spain to repatriate her were ultimately unsuccessful. She was decommissioned and sold for scrap in 1957, marking the end of her long service history.

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