TAIPEI (Taiwan News) — Taiwan’s first indigenous submarine, the Narwhal, conducted its first shallow dive Thursday as it moves toward Navy commissioning in June, reports said.

Both shallow and deep diving tests were originally to be completed before the handover to the Navy in November. Under the contract, shipbuilder CSBC Corporation Taiwan must pay delay penalties estimated at NT$190,000 (US$6,000) per day.

The Narwhal was expected to dive to between 10 m and 50 m off the coast of Kaohsiung on Thursday, Liberty Times reported. The next phase is expected to include deep-diving tests to depths of more than 200 m south of the island of Xiaoliuqiu.

CSBC announced the shallow-diving test in advance, saying the aim is to assess the submarine’s underwater stability, system integration, and watertightness. The Narwhal will still face a range of tests before and after delivery to the Navy, the company said, adding that its manufacturing period has not taken much more time than similar submarines in other countries. Design work on the Narwhal began in 2017, manufacturing began in 2020, and the first tests took place last June, per CNA.

The submarine’s latest foray into the Taiwan Strait drew military enthusiasts onshore waving Taiwan flags and banners expressing support for the Navy and the submarine program. Some left their homes in Tainan at 6 a.m. to drive to Kaohsiung, where the Narwhal appeared around 10 a.m. for the start of its journey.