TAIPEI (Taiwan News) – Taiwan’s first indigenous submarine was seen cruising in the port of Kaohsiung on Saturday in what was described as the final phase of its harbor acceptance tests.

If no problems emerge, the Narwhal could soon begin undergoing sea acceptance tests, per CNA. The sea phase had previously been scheduled to start in April, but Navy officials are still insisting the commissioning will take place in November as originally planned.

The Narwhal left shipbuilder CSBC Corporation on its own engine power Saturday afternoon. About a dozen engineers were seen on deck, while a small ship accompanied the submarine on its journey, the report said.

The Narwhal traveled three times back and forth between 1 p.m. and 4 p.m., with restrictions in force for other shipping in that part of the harbor, the Liberty Times reported.