Kaohsiung, Jan. 29 (CNA) Taiwan's indigenous defense submarine (IDS) prototype sailed out of Kaohsiung Harbor on Thursday to begin its first-ever submerged tests. The submarine, christened Hai Kun, or Narwhal in English, departed the harbor at around 10 a.m. Dozens of military enthusiasts gathered along the waterfront for the occasion, many waving the Republic of China (Taiwan) flag and chanting "Let's go, Hai Kun!" Military enthusiasts wave banners saying "Let's go, Hai Kun!" The Hai Kun was originally scheduled to complete sea trials by November 2025, but the timeline was pushed back as it underwent final adjustments ahead of the submergence tests.