Time Running Out in Search for Missing Sub

Watchstander aboard the Royal Navy ice patrol ship HMS Protector keeps a lookout for the ARA San Juan (RN)

By The Maritime Executive 11-21-2017 08:54:18

The international search effort for the missing Argentine submarine ARA San Juan will benefit from calm weather this week, and just in time: the sub’s supply of breathable air is likely running low, according to the Argentine Navy.

On Tuesday, swells were expected to fall to six feet from the 20-foot levels off Patagonia Sunday and Monday. “Luckily, from today onwards the intensity of the wind and the height of the sea will begin to fall,” said Argentine Navy spokesman Enrique Balbi.

However, the search coalition has suffered a series of setbacks. Four separate sets of clues to the San Juan's location have all turned out to be false alarms. A sequence of satellite call attempts turned out to be from another vessel using the sub's frequency; a large life raft found in the search area was from a different vessel; a series of white signal flares sighted by search vessels could not have originated from the sub, which only carried red flares; and a sonar signature that was believed to be the sound of tools banging on the interior of the sub's hull turned out to be from a "biological source." “The sounds are not from the submarine and do not correspond to a pattern that could be interpreted as Morse code,” Balbi told reporters. 

Time is running out for the search, as the San Juan only had a seven-day supply of oxygen when she disappeared on Wednesday. The foul weather over the weekend means that it is unlikely that she could have come close enough to the surface to refresh her air.

The ARA San Juan has been out of radio contact since November 15, when she called shoreside commanders to report minor difficulties with her batteries. The sub and her 44 crewmembers were ordered to return to the naval base at Mar del Plata for repairs, and the vessel’s last known position was about 240 nm off the coast of Patagonia, near the San Jorge Gulf. The U.S., UK, Chile, Brazil and other countries have contributed assets to the search, and a total of nearly 50 ships and aircraft are actively looking for the missing vessel. In addition, the U.S. Navy has dispatched high-tech unmanned underwater vehicles to aid in a search of the seafloor, along with two complete sets of subsea rescue equipment capable of bringing the sub's crew back to the surface.