Haunting video has emerged of the crew on board a doomed submarine before they died.
Indonesian authorities confirmed on Sunday 53 people on board the 44-year old KRI Nanggala-402 had died in the Bali Sea.
The submarine lost contact on Wednesday during a dive drill.
Video has now emerged of the crew gathered around with an acoustic guitar singing “Sampai Jumpa”, which means “I wish all the best for you”.
The men are heard singing: "Even though I'm not ready to be missing you. I'm not ready to be without you. I wish you all the best."
Military spokesman Djawara Whimbo told Agence-France Presse the song was recorded as a farewell for an outgoing commander whose successor took on the role in March.
Erix Soekamti, the original singer of the song, shared the video on Instagram two days ago with the caption: “Pray for Nanggala 402."
‘Brutally sad’ video breaks hearts
On YouTube, people shared their distress at watching the video.
“This broke my heart,” one woman wrote.
Another called it “brutally sad”.
The German-built submarine was discovered lying on the seabed on Sunday broken into at least three parts, four days after it lost contact while preparing to conduct a torpedo drill.
Grieving relatives gathered on the seashore in Bali on Monday to pay their respects to the sailors who died and urged authorities to bring up their bodies from the depths.
Experts say it will be a daunting task to lift the submarine to the surface from the deep water, requiring specialised salvage equipment.
A spokesman for Indonesia's navy said a retrieval operation was still being discussed with experts and international bodies.
"We will analyse the underwater pictures and video, the current et cetera to decide the technology that will be used," First Admiral Julius Widjojono said.
A sonar scan detected at least three parts of the submarine at a depth of 850 metres, far beyond Nanggala’s diving range.
Relatives of crew member I Gede Kartika congregated at Celukan Bawang on Bali's north coast on Monday.
Some carried incense and flowers as they clutched framed photographs of him in his naval uniform. Others rowed out to sea to ceremoniously scatter petals in the water.
Family members of another lost crew member also gathered at the port town of Banyuwangi, which is home to the naval base on Java island where the Nanggala was stationed, to pay their respects.
President Joko Widodo offered his condolences to the relatives and pledged the state would fund the education of the dead sailors' children.
Do you have a story tip? Email: email@example.com