Although senior aides said sabotage couldn't be discounted, Argentine Defense Minister Arturo Puricelli said he faced an embarrassing encounter with President Cristina Fernandez de Kirchner over the incident.
"I'll be ashamed, frankly, to tell her that a boat sank while tied to the dock," Puricelli told Argentine media.
He said neglect or sabotage couldn't be ruled out and government officials would be looking for a "well-founded reason" for the sudden demise of ARA Trinidad, a destroyer that led Argentine invasion of British-ruled Falkland Islands in 1982.
Since that conflict, Argentina's government, military and citizens have carried on a strange relationship with the vessel, which was praised in populist accounts of the war but remained neglected once moored.
Plans for the ship's preservation and refurbishment never got off the ground. Instead the vessel was used as a source of spare parts for other naval ships and was cannibalized in parts even amid the talk of preserving it for posterity.
Faced with criticism, officials blamed Argentina's underfunded navy for failing to take care of what many Argentines regard as a part of Argentina's naval history.
Fernandez has revived Argentina's claim on the Falkands, which she calls Islas Malvinas. Critics of the president within the opposition say the anti-British rhetoric is meaningless if Argentina cannot maintain a mothballed warship at its moorings.
Argentine media are full of pronouncements of dismay and shame over the incident. Argentine military hopes the embarrassing incident will prod the president to put into action frequently promised allocations for naval regeneration.
Two years ago Fernandez announced a five-year program for increased defense spending on military refurbishment, plans to modernize all armed forces and replace aging naval fleet. Little progress has been made on that program.
Argentina also says it is developing a nuclear-powered submarine but information on the project remains scant.
A military-led invasion of the Falkland Islands in 1982 sparked a 74-day conflict that caused deaths of more than 1,000 people, including Falklanders and Argentine and British military personnel. Argentina signed a formal surrender to Britain before retreat, but in 1994 added its Falklands sovereignty claim to its revised constitution.
Ricardo Burzaco, analyst and director of the Mercosur Defense and Security magazine, said Argentina was determined to improve the state of its defense infrastructure but the present plans would not amount to a sufficient increase in defense acquisitions.
Argentina has been shopping around and has been offered military equipment and hardware on easy terms by China and European suppliers. Russia has indicated it will extend favorable credit terms to Buenos Aires and replace mostly obsolete U.S. equipment with its own inventories.
Burzaco indicated any acquisitions under the program might fall short of the Argentine military's real needs, which are diverse and widespread across all sectors, requiring vast expenditure.
Argentina's military was one of the best equipped in the region right up to the 1950s under military rule.
More recently it faced sharper expenditure cutbacks than most other Latin American armed forces. Real military spending declined after Argentina's Falklands defeat. Despite recent increases, the defense budget stands well below target.