Rescuers have sent more than a dozen search helicopters and ships to the area where contact was lost, with the US, Australia, Singapore, Malaysia, and India providing assistance.
According to Yudo, the submarine had only enough air to last until around dawn on Saturday if it had lost power, but that this could be stretched for five days if the vessel had retained electricity.
But even that assessment on oxygen was optimistic, according to experts, because it assumed the submarine had not been crushed by water pressure.
“Now it'll be up to the investigators to establish the chronology of events and determine the cause. At the same time, plans would have been made to assess the feasibility of retrieving the sub at such extreme depth,” said Collin Koh, Research Fellow at the Institute of Defence and Strategic Studies.
“It's technically possible to do it, though I believe Indonesia will have to engage foreign assistance in this.”