The schooner of war San Antonio was built in Baltimore by Schott and Whitney and commissioned into the Texas Navy on August 7, 1839. She sailed for a time under the name Asp and was a sister ship of the San Jacinto and the San Bernard. The San Antonio measured sixty-six feet in length and twenty-one feet across the beam and had a draft of 21½ feet. She displaced 170 tons of water. The schooner carried a complement of thirteen officers and sixty-nine sailors and marines and was armed with four twelve-pound medium cannons and one twelve-pound long-range pivot cannon. The San Antonio was commanded from November 1839 through January 1840 by Lt. Francis B. Wright. Lt. J. O'Shaunessy held temporary command in February but was superceded by Lt. Alexander Moore, who served as captain until June 1841, when Lt. William Seeger took command. The San Antonio joined Commodore Edwin W. Moore's fleet at the Arcas Islands off the coast of Yucatán in late August or early September 1840 and spent the next two months cruising off the Mexican coast. At the end of October she returned to her home port, Galveston, bearing home James Treat, the Texas diplomatic agent in Mexico, after a failed attempt to gain recognition for the Republic of Texas. Thereafter the San Antonio was kept on patrol in Texas waters conducting surveying and cartographic operations and suppressing smuggling.
On December 13, 1841, she sailed once more for the Bay of Campeche to cooperate with the rebellious Mexican state of Yucatán. The San Antonio, with the San Bernard and Moore's flagship Austin, reached Sisal on January 6, 1842, but on January 31 she was returned to Galveston with dispatches from Moore, while the remaining two Texas ships cruised the Mexican coast in search of prizes. Secretary of war and marine George Washington Hockley sent orders to Moore by way of the San Antonio to return to port immediately, but the schooner was to call first at New Orleans to land the survivors of a shipwreck and to procure supplies for the fleet. While riding at anchor in the Mississippi River on February 11, 1842, the San Antonio hosted the first and only mutiny of the Texas Navy. While the ship's high-ranking officers were ashore, the sailors and marines were confined to quarters for fear of desertion. After drinking a quantity of liquor smuggled aboard by local boatmen, marine sergeant Seymour Oswald demanded shore leave of the lieutenant of the watch. When denied, Oswald became quarrelsome, and Lt. Charles Fuller called out the guard, of which Oswald was the commander. Oswald issued arms to his companions in rebellion and then struck Fuller in the head with a hatchet. Fuller responded with his Colt revolver. In the ensuing melee Fuller was killed, two midshipmen were seriously injured, and a second lieutenant was knocked below decks and there confined. Oswald and his fellow mutineers were quickly apprehended by the United States revenue cutter Jackson, but only two were returned to their ship; the remaining eight were held in the local jail, and attempts at extradition failed.
From New Orleans the San Antonio ran down to the Arcas Islands and from there to Sisal. Moore then detached her to Laguna to pick up Francis R. Lubbock, a survivor of Governor Mirabeau B. Lamar's Texan Santa Fe expedition, who had escaped his captors and made his way to Yucatán. The ship then rejoined the fleet at New Orleans on July 1. Moore dispatched the schooner to Yucatán on or about October 1 by way of Galveston and Matagorda to attempt to raise funds for the fast-failing Texas fleet. She never reached Campeche, however, but was lost at sea. Although the state of Louisiana refused to return some of the mutineers who had killed Lieutenant Fuller the previous February, and although many witnesses had gone down with their ship in September, Commodore Moore tried those hands in Texas who were aboard his flagship in April 1843. One man was sentenced to fifty lashes with the cat o' nine tails and two more to 100 each. Four others were sentenced to death and were hanged from the yardarm of the Austin on April 26. Sergeant Oswald escaped jail in New Orleans and was never brought to justice. Frederick Shepard, a mutineer who saved his life by testifying against his fellows, was killed in action three weeks later in a battle off Campeche.