TAIPEI (Taiwan News) — Taiwan’s first indigenous-built submarine prototype, the Narwhal, conducted its fifth dive test Tuesday off the coast of Kaohsiung.

Despite chilly weather, military enthusiasts gathered at the harbor to watch the vessel depart and cheer on its crew. Observers unfurled a flag and shouted, “Go Narwhal! Go Navy!” as the submarine headed toward open waters, per CNA.

The submarine left port at about 8 a.m. for sea trials before carrying out its latest underwater test. Military analysts said additional tests are expected to continue this week and overnight trials are possible in the future.

Military expert Chi Tung-yun (紀東昀) said the latest outing marked the Narwhal’s 11th sea trial and its fifth dive test. Chi said the vessel has undergone adjustments and optimization following the previous four underwater dives.

He noted that the sonar system is particularly important, as engineers must ensure the submarine does not generate excessive noise at greater depths. Such operational factors typically require multiple rounds of testing, he said.

Chi added that the interval between sea trials has been shortening, suggesting that inspections and testing have been progressing smoothly. Future trials may include overnight voyages to conduct endurance testing, including monitoring battery power consumption at different depths and speeds, he said.

According to underwater footage released in February by CSBC Corp, previous sea trials recorded underwater and aerial views of the steering control system and exhaust valve operations. The video also documented the raising and lowering of the periscope and antenna mast, decoy launches, surfacing procedures, and the submarine’s return to port.