Taiwan's first home-built submarine is nearing delivery, a milestone for the island's defense, though it will not be combat-ready for months after handover.

• The Hai Kun left Kaohsiung for its 23rd sea trial and 17th dive test, with the shipbuilder's engineers fine-tuning systems based on earlier runs.
• Testing has entered its final stretch, and trials are expected to come thicker and faster in the next few weeks.
• The navy and shipbuilder Taiwan International Shipbuilding still aim to hand the boat over by the end of the year, despite daily late-delivery penalties.
• Handover will not mean battle-ready: further evaluation, system tuning, and tactical validation will take at least six months to a year.

Outlook: Expect denser sea trials through year-end as both sides push to close out the handover on schedule.