SINGAPORE - Singapore's submarine rescue vessel, MV Swift Rescue, arrived in waters north of Indonesia's Bali island early on Sunday (April 25) to join an international search for a missing submarine, hours after the Indonesian authorities declared the vessel with 53 crew members on board had sunk.
"This tragedy has shocked us all," said President Joko Widodo in a broadcast statement on Sunday.
"We convey our deep sorrow for this tragedy, especially to families of the submarine crew. They are the best sons of the nation, the best patriots who guard the sovereignty of the country."
"We will continue to put our best efforts in the search and rescue. Let's send our prayers and best wishes to the 53 best patriots who have guarded the country's sovereignty. And (pray) that all their family members be given patience, fortitude, and strength," he added.
Preparations are being made to salvage the KRI Nanggala-402 from a depth of 850m, Indonesian Navy Chief of Staff Admiral Yudo Margono said on Saturday.
As the submarine had plummeted deeper than the 500m it could withstand, it is likely to have been crushed by water pressure and cracked, he said, conceding that evacuation at such depths would be difficult.
The submarine was taking part in torpedo-firing drill off Bali on Wednesday when it dove and lost contact.
Debris, including a torpedo fragment, prayer mats and periscope lubricant, have been recovered from the area where the submarine last made contact. The nature of the debris suggested an external pressure or a crack in the torpedo launcher, Admiral Yudo said.
Earlier, searchers had detected an oil spill and an unidentified object with high magnetism at a depth of 50m to 100m.
Oxygen supply, which could last 72 hours from the time the 44-year-old German-built submarine went down, was believed to have run out earlier on Saturday.
The navy has since raised the status of the submarine from "sub miss" to "sub sunk", a military term for sinking. The tragedy marked the first-ever submarine disaster in the South-east Asian nation dogged by ageing military equipment and weaponry.
The MV Swift Rescue, dispatched by the Republic of Singapore Navy (RSN) on Wednesday afternoon, joined two dozen Indonesian vessels, as well as a sonar-equipped Australian warship and a US P-8 Poseidon surveillance plane. Deep-search-and-rescue vessels from Malaysia and India are on the way.
The MV Swift Rescue is equipped with a Deep Search and Rescue Six (DSAR 6) submersible vessel which can reach up to 500m underwater, attach itself to a stricken submarine and rescue its occupants.
"The MV Swift Rescue immediately got to work after its arrival at around 2am," an official who declined to be named told The Straits Times.
"It carried out underwater detection with its multi-beam sonar and remote operation vehicle, following up the findings of Indonesia's own hydrographic survey vessel, KRI Rigel," he added.
A press conference by the Indonesian Navy is expected later on Sunday.
Confirmation of the loss of the submarine has devastated Indonesians, many of whom have gone online to express their condolences and sorrow.
The #PrayForKRINanggala402 hashtag has been trending on Twitter.
"Dear Ocean, please send them to the doors of Paradise," said Twitter user @edetgab.
However, some still harbour hopes the crew would be found alive and could return to their families. Twitter user @ro63250399 said: "May a miracle happen."