Kaohsiung: The Hai Kun (Narwhal), Taiwan's first indigenously constructed submarine, set sail from the Port of Kaohsiung on Monday morning to engage in its latest series of sea trials, which featured dive tests.

According to Focus Taiwan, the trial marked the submarine's 15th sea trial overall and ninth submerged-navigation test. The trials followed a prior attempt scheduled for May 29, which was delayed due to adverse weather conditions.

Shipbuilder CSBC Corp., Taiwan, has been accruing penalties after missing a November 2025 deadline owing to "testing delays." However, in February, the company expressed its intention to deliver the submarine to the Navy by June. Defense Minister Wellington Koo emphasized that the testing process would adhere to established procedures, prioritizing safety and quality to meet defense capability requirements.

Military expert Chi Tung-yun highlighted the necessity of gathering key performance parameters during testing, noting that reducing environmental variables is crucial for obtaining accurate data. Chi mentioned that the Hai Kun's forthcoming assessments would include eagerly awaited seaworthiness and deep-diving trials, along with overnight evaluations. He added that if these tests are successfully completed, the submarine could be delivered between July and September.