The Indonesian government has pledged to pay compensation to the families of the 53 crew who died after submarine KRI Nanggala-402 sank in deep waters in the north of Bali last week. It also said that it would fund the education of their children.

Most of the submariners, some still in their 20s, were the breadwinners of their families.

In Banyuwangi, East Java, weapons operator Pandu Yudha Kusuma, 22, leaves behind his wife of two months Mega Dian Pratiwi.

In Sidoarjo, pump operator Rusdiansyah Rahman's wife delivered their baby early this month, while Colonel Harry Setyawan, the commander of Indonesia's submarine fleet, was a father of four children.

President Joko Widodo is set to hand over compensation to the families of the crew today at Juanda naval air base in Surabaya.

He had earlier described the submariners as "Indonesia's best compatriots", "the guardians of the country's sovereignty", and vowed to offer appreciation and compensation to their families.

"The state will give them one rank higher and award them star medals for the dedication, services and sacrifices of these best warriors," the President said on Monday. "The government will also sponsor the education of the children of the KRI Nanggala-402 crew until undergraduate degrees."

Indonesia's first major submarine incident has shaken the nation, with displays of grief nationwide. Pictures and videos of the crew circulated in WhatsApp groups and were posted on social media to remember those who died.

Indonesian Defence Minister Prabowo Subianto offered his condolences on Instagram over the tragedy. Among those who died was Mr Rhesa Tri Sigar, the son of Mr Prabowo's cousin Godfried Sigar, a military officer.

In Banyuwangi, Mr Wahyudi, 52, the father of Mr Pandu, had prepared a pair of military shoes for his son.

The army officer said the shoes were from his office and during a nearly five-minute video call on April 18, Mr Pandu, clad in his black sailor uniform, had described the shoes as "nice".

Father and son share the same shoe size.

"Once you return, you can take the shoes, I told him," Mr Wahyudi told The Straits Times. "Unfortunately, that was the last time I saw him."

Amid the grief, Mr Wahyudi said he was also proud of his son, who had dreamt of becoming a military officer since he was a child.

"For us military officers, to die on duty is an honour... That makes me proud even though I still can't see his body till now."

Mr Ari Suryadi, a teacher who handled student affairs at a public vocational high school in Banyuwangi where Mr Pandu studied from 2013 to 2016, recalled that he was "very active" in various school events.

He added Mr Pandu was always helpful and keen to share his knowledge with his juniors, including training them in flag-hoisting duties for ceremonies on weekends.

"Pandu has strong leadership skills," he told ST. "He was quick to move and mobilise his friends even before he was instructed."

Mr Giyat Purnomo, a schoolmate of another submariner, Mr Dedi Hari Susilo, said that he was quiet and always got things done, but was open and friendly.

He had met Mr Dedi at a Vespa scooter club a few years ago, where he learnt about the sailor's tough journey to enter military service.

"He failed three tests to join the army and then took another two for the navy before making it in the last one. It really tells about his persistence."

He added: "He had enjoyed what he deserved with his hard work. He had achieved his long-fought ambition."