Hai Kun submarine begins late-stage sea trials ahead of delivery

Taiwan's indigenous submarine prototype Hai Kun put to sea from Kaohsiung on Friday morning for another round of trials, Central News Agency reported. Military commentator Chi Tung-yun, chair of the Taiwan Security and Development Association, told local media the sortie was the boat's 23rd sea departure and 17th submerged test.

CNA said Hai Kun is now in the later phase of sea trials, with factory technicians still assisting adjustments based on earlier results. Chi assessed that trial tempo may rise in the coming weeks as the programme finishes preparations required before delivery to the Navy.

United Daily News coverage of the same Oct. 2 departure likewise described the 17th dive and noted that CSBC Corporation Taiwan has already accrued substantial daily late fees while testing continues under a safety-first approach. UDN put cumulative penalties near NT$57 million after roughly ten months of day-rate charges.

Navy Headquarters has declined to lock a public delivery date. UDN recalled that Navy Chief of Staff Vice Admiral Chu Hui-min recently told a Ministry of National Defense briefing that Hai Kun is still in equipment inspection and calibration under the test procedure book, and that CSBC would announce concrete progress when warranted.

Chi stressed that delivery would not equal immediate combat readiness. As Taiwan's first domestically built submarine, Hai Kun would still need follow-on evaluation, systems optimisation, and tactical validation that could take at least six months and possibly more than a year after handover, CNA reported.

Background reporting in Taipei Times in late September had already framed October as a possible delivery window while emphasising that unfinished trials and penalties would not override safety sequencing. Friday's sortie fits that late-stage pattern rather than a ceremonial acceptance cruise.

Photographs published by CNA showed hull number 711 leaving Kaohsiung Harbour under clear conditions, consistent with an incremental correction sortie rather than a one-off demonstration. The images document the boat under way after previous adjustments, which Chi said remain the focus of current testing.

Programme managers must still close remaining trial cards before legal transfer from the builder to the fleet. Even after transfer, navy crews would continue weapons, sensors, and tactics work-ups before Hai Kun could be counted as a deployable undersea asset in Taiwan's order of battle.

The indigenous submarine project remains central to Taiwan's plan for a more survivable undersea force able to operate in the shallow and contested waters around the island. Each late-stage sortie therefore carries political as well as technical weight as Taipei seeks to show that the prototype is converging on a deliverable configuration.

Observers watching Kaohsiung will look next for denser trial days and any official notice that acceptance trials have begun. Until those signals appear, Friday's 23rd sea run stands as evidence that Hai Kun is still in builder-supported refinement rather than fleet service.

For now, CNA and United Daily News reporting converge on three points: the Oct. 2 trial happened, submerged testing continues under OEM support, and post-delivery tactical validation will stretch well beyond the handover ceremony itself.

This report was produced through TaiwanDefence’s automated publishing system and includes links to its supporting sources.