USS Ardent ( AM - 340 ) The second USS " Ardent " ( AM - 340 ) was a in the United States Navy . " Ardent " was originally laid down as " HMS Buffalo " ( BAM - 8 ) , for the Royal Navy on 20 February 1943 at Alameda , California , by the General Engineering & Drydock Co . ; rescheduled for delivery to the United States Navy ; renamed " Ardent " and redesignated AM - 340 on 24 May 1943 ; launched on 22 June 1943 ; sponsored by Mrs . Bernadette Armes , the daughter - in - law of George A . Armes , President of the General Engineering & Drydock Co . , and commissioned on 25 May 1944 , Lt . Comdr . Allan D . Curtis in command . World War II Pacific operations . During the first seven months of her career , " Ardent " escorted convoys and ships operating between the west coast of the United States and the Hawaiian Islands , though she also ranged as far as Eniwetok in the Marshalls and Tarawa in the Gilberts . Sinking of the Japanese submarine I - 12 . The highlight of her service during this period occurred on 13 November . " Ardent " and the frigate were escorting a six - ship convoy midway between Honolulu and the United States . At 12 : 32 , " Ardent " ' s sonar picked up a submarine contact . " Ardent " attacked first at 12 : 41 , firing a 24 - charge " hedgehog " pattern , and again at 12 : 46 with a second " hedgehog " pattern . " Rockford " left her escort station to assist , and fired her first barrage of rocket s from her " hedgehog " at 13 : 08 ; two explosions followed , before an underwater detonation rocked the ship . " Ardent " carried out two more attacks and the frigate dropped 13 depth charges to administer the coup de grace . The resulting explosions caused a loss of all contact with the enemy submarine . Wreckage recovered on the scene — deck planks , ground cork covered with diesel oil , a wooden slat from a vegetable crate with Japanese writing and advertisements on it , pieces of varnished mahogany incribed in Japanese , and a piece of deck planking containing Japanese builders ' inscriptions — indicated a definite " kill " . Postwar research revealed the sunken submarine to be the , which had sailed from the Inland Sea on 4 October 1944 to disrupt American shipping between the west coast and the Hawaiian Islands . In sinking " I - 12 " , " Ardent " and USS Rockford unwittingly avenged the atrocity I - 12 had perpetrated on 30 October when , after sinking the Liberty ship SS John A . Johnson , the submarine had rammed and sunk the lifeboats and rafts and then machine - gunned the 70 survivors . Among the ten men killed were five enlisted men of the merchantman ' s Navy armed guard detachment . Second Pacific deployment . On 1 December 1944 , " Ardent " departed San Francisco , California , and headed for Hawaii . She reached Pearl Harbor on the 10th and underwent an intensive training period before sailing for the Marshall Islands on 27 January 1945 with Task Group ( TG ) 51 . 11 , arriving on 5 February at Eniwetok . Two days later , " Ardent " sailed for Tinian , and reported for duty with TG 52 . 3 on the llth . On 13 February , the ship got underway , in company with , , and , to participate in the Iwo Jima campaign . She conducted minesweeping operations off that island during the day from 15 to 18 February , and each night , her group retired to screen . During the sweeps , the ships came under intermittent fire from enemy shore batteries , but sustained no damage . On 19 February , " Ardent " took bomb - damaged in tow and proceeded to the Marianas as escort for a convoy of damaged LCI s . Ship shoots down Japanese planes . Upon reaching Saipan on the 25th , the minesweeper embarked 20 marines and loaded 149 sacks of mail for delivery at Iwo Jima . She arrived back at that island on 1 March but shaped a course for Ulithi the next day as escort for Task Unit ( TU ) 51 . 29 . 3 . A few weeks later , " Ardent " got underway with TG 52 . 4 to take part in the assault on Okinawa . She began minesweeping operations on the 24th and continued them through the 31st , the unit to which she was attached destroying 17 mines during this time period . During frequent enemy air attacks , the minesweeper took several Japanese planes under fire . On 26 March , an enemy plane under fire from the nearby fast minelayer started a glide for USS " Ardent ' s " stern . The minesweeper opened fire and splashed the plane away . On four occasions on 28 March , Japanese aircraft approached " Ardent " and her consorts . An adjacent formation shot down the first , from USS " Ardent ' s " port beam . Combined fire from " Adams " and " Ardent " , as well as other ships in the formation , splashed the second , on the port beam . " Ardent " opened fire on the third aircraft , and saw it splash , the victim of a barrage put up by a formation of ships on the starboard quarter . USS " Adams " accounted for the fourth enemy aircraft . Later that same day , the minesweeper struck a mine and sank ; " Ardent " rescued 19 survivors . Okinawa landings . Following the completion of minesweeping operations , " Ardent " assumed station on a patrol screen . On L - day , the day of the landings at Okinawa , 1 April 1945 , a suicider crashed the nearby , causing extensive damage . During this period , " Ardent " opened fire on several Japanese planes , but scored no hits . Stateside repair period . Ordered to proceed to Saipan for engine repairs , " Ardent " sailed for her destination on 4 April , and arrived on 10 April . Since parts necessary for the repairs were not available in the forward areas , she was routed via Pearl Harbor , to Seattle , where she arrived on 30 May . " Ardent " underwent engine repairs at Seattle , Washington until 7 August . Six days later , on the 13th , the minesweeper sailed for Pearl Harbor , and was at sea , en route to the Hawaiian Islands , when the war with Japan ended . Post - World War II operations . Departing Pearl Harbor on 20 August in company with and , " Ardent " called at Saipan from 13 to 17 September , and arrived at Okinawa on the 21st . Pushing on for Japan , " Ardent " moored at Sasebo , Japan , on 27 September , disembarking passengers , and delivering mail and freight . The ship made a brief trip back to Okinawa , arriving there on 2 October , before she returned to Sasebo on 20 October . During her time at Okinawa , she sortied on 7 October to ride out a typhoon , and conducted sweeps down the island ' s east coast for survivors of that storm . Joining TU 52 . 4 . 1 on 27 October , " Ardent " proceeded to the " Klondike " minefield area , located in the East China Sea southwest of Kyūshū . She conducted daily minesweeping operations until 8 November , when she arrived back at Sasebo . Between that time and the end of the year , " Ardent " operated between Honshū and Kyūshū , escorting ships , transporting minesweeping gear , and observing Japanese minesweeping operations and conducting demolition firing at the mine disposal grounds at Kushikino Ko . She remained thus engaged into March 1946 . Routed to Kobe on 4 March 1946 , in company with , " Ardent " sailed for the Hawaiian Islands two days later , on 6 March . Touching at Saipan , Eniwetok , Johnston Island and Pearl Harbor , the minesweeper continued on to the west coast of the United States ; parting company from USS " Defense " on 16 April , " Ardent " dropped anchor in San Francisco Bay on 19 April . Stateside inactivity . The minesweeper lay in the San Francisco Naval Shipyard until November 1946 . Subsequently proceeding to San Diego in company with , " Ardent " then operated in the vicinity of San Clemente Island , Newport Beach , and Oceanside , California , and on air - sea rescue stations off the coast of southern California . Returning to pier 17 , Treasure Island ( California ) , on 15 December 1946 , to commence preparations for inactivation , " Ardent " shifted to the San Diego Naval Station on 22 January 1947 . Decommissioning . Placed out of commission , in reserve , on 30 January 1947 , " Ardent " was berthed with the San Diego group of the Pacific Reserve Fleet . While she was in reserve , the ship ' s designation was changed to MSF - 340 on 7 February 1955 . Struck from the Navy List on 1 July 1972 , the ship was subsequently sold to the government of Mexico on 19 September 1972 . Mexican Navy service . On 19 September 1972 , the former " Ardent " was sold to the Mexican Navy , which renamed her ARM " Juan N . Álvarez " ( C77 ) . Her pennant number was later changed to G09 , before being changed a final time to P108 in 1993 . , " Juan N . Álvarez " Awards . " Ardent " earned four battle star s for her World War II service .