Admiral Yudo Margono, chief of staff of the Indonesian navy, said the submarine has enough oxygen for 72 hours, based on calculations from the time the ship lost contact during a military exercise on Wednesday.
The German-made KRI Nanggala-402 asked permission to dive or dive on Wednesday at 3 a.m. before losing contact, authorities said. Margono said the submarine had just fired two torpedoes – one with live ammunition and one with a practice warhead – as part of training exercises in the Bali Strait, a stretch of water between the islands of Java and Bali that connects the Indian Ocean and the Sea. Bali.
Answering questions about the submarine’s condition before participating in the war simulation, Margono said the KRI Nanggala-402 and all its crew are well prepared. He last docked for maintenance in 2020 in Surabaya, a port city on the island of Java, he said.
The military suspects that an oil spill observed on Wednesday in the air surveillance near the diving point came from the boat. Margono said the Navy also found an object at a depth of 50-100 meters (about 164-328 feet) that was magnetic, meaning it probably came from the submarine.
Margono said there are two possibilities to explain the oil spill observed at the surface: the submarine tank could leak because it sank too deep or the submarine released fluid on board in an attempt to rise to the surface.
Indonesian Navy spokesman First Adm. Julius Widjojono said the submarine had the ability to sink up to 500 meters (about 1,640 feet) below sea level, but authorities estimate that it dropped 100-200 meters below that depth.
Two ships equipped with side-scan sonar, a tool used to map the seabed, began searching the area on Wednesday, the Defense Ministry said, while a Rigel warship equipped with sophisticated sonar that can accurately detect the ship’s position is on its way to Jakarta, according to Widjojono.
Authorities say the crew is safe, but have acknowledged that the situation could be fatal at this depth.
“Let’s pray for them so they can survive,” Widjojono told local media on Wednesday.
The International Submarine Evacuation and Rescue Office (ISMERLO), an organization that facilitates an international response to distressed submarines, is also providing assistance, the Defense Ministry said.
The 1,395-ton KRI Nanggala-402 was built in 1977 by German shipbuilding company Howaldtswerke-Deutsche Werft (HDW) and joined the Indonesian navy in 1981, according to a ministry statement.
The submarine underwent a two-year restoration in South Korea, which was completed in 2012, according to the Indonesian cabinet secretariat.
In the past, Indonesia operated a fleet of 12 submarines purchased from the Soviet Union to patrol the waters of its vast archipelago. But it now has a fleet of only five, including two German-type 209 submarines and three newer South Korean ships.
Indonesia has sought to improve its defense capabilities, but some of its equipment is still in operation and has resulted in fatal accidents in recent years, especially involving the aging of military transport aircraft.
CNN’s Kara Fox contributed to the report.