Special Report: Indonesia seeks asymmetric deterrence with autonomous submarine

Indonesia's prototype KSOT submarine, seen here during its sea trials. (Janes/Ridzwan Rahmat)

Indonesia's indigenously developed autonomous submarine, designated the Kapal Selam Otonom (KSOT), has moved from concept to procurement.

In a June 2026 interview with Janes at the company's shipyard in Surabaya, PT PAL CEO Kaharuddin Djenod confirmed that the Indonesian Ministry of Defence (MoD) has signed a contract for an undisclosed number of KSOT units.

These early units will be fielded by the Indonesian Navy for evaluation and could support the development of underwater warfare doctrine, Djenod said.

Asymmetric warfare

Developed by state-owned shipbuilder PT PAL, KSOT is intended to offset better-equipped adversaries through scale, ambiguity, and cost imposition.

According to Djenod, Indonesia recognises that it cannot outspend better-funded adversaries, who in recent years have bolstered their fleets with larger numbers of modern submarines and combatants.

A long-term proponent of the concept, Djenod described KSOT as a personal project. Before joining PT PAL, he operated a private enterprise focused on underwater vehicles, where he built and tested early prototypes.

“It was only at PT PAL that I could finally implement KSOT,” he said, citing support from the MoD and Indonesian President Prabowo Subianto.

This background positions KSOT as the culmination of a long-standing vision on unconventional naval warfare, enabled by recent technological advances and operational lessons from recent conflicts.

Djenod linked the KSOT programme directly to the rapid advancement and miniaturisation of artificial intelligence (AI)-optimised chips, underwater sensors, and communications equipment.

“Advances in AI, sensor, and control technologies mean it is no longer just possible, but necessary, to develop weapons that do not involve humans inside them,” he said.