Theories about the sinking...attention now turns to recovery
"As an Indonesian navy submarine crewed by 53 men glided below the surface of the Bali Sea during a routine training exercise, it may have been hit by an invisible but powerful force that dragged them to the deep.
Indonesian navy officials suspect an internal solitary wave, known to occur in the seas around Bali, may have caused the sinking of KRI Nanggala 402, and the loss of its 53 crew.
The vessel sank to a depth of 838 metres, far beyond the reach of rescuers.
Many theories have been put forward but authorities now say there is evidence an underwater wave — that can exert an intense vertical pull below the sea surface — occurred in the Bali Sea around the very time the submarine disappeared last Wednesday morning."
"Rear Admiral Muhammad Ali, a former commander of KRI Nanggala 402, and now an assistant of planning and budgeting in the Indonesian navy, said an internal wave was effectively "a strong current which can drag the sub vertically so it would sink faster than it should."
"Our suspicion falls on natural conditions. Because an internal solitary wave occurred at that time in the north of Bali," he told Indonesian media this week.
Indeed, navy officials say images from Japan's Himawari 8 satellite, as well as European satellite Sentinel showed there were large underwater waves that coincided with the KRI Nanggala 402 sinking.
"It moved up from the bottom to the north, and there's a trench between two mountains," said Rear Admiral Iwan Isnurwanto, Commander of the Indonesian Navy Command and Staff School.
"The wave was about two nautical miles [in speed] and the volume of water was about two to four million cubic litres.""