Taiwan's first indigenous defense submarine has begun sea trials.

The Narwhal was seen sailing out to sea from C-S-B-C's shipyard at the Port
of Kaohsiung where it had been moored.

The prototype recently finished a harbor acceptance test.

Sources say the vessel is now undergoing various tests involving its
propulsion and navigational systems, while part of it is above the surface.

The Navy has deployed armed ships to protect the area where sea trails are
taking place.

The Air Force is also reportedly sending planes to monitor the sea trials and
ensure the prototype submarine's safety.

A sea acceptance test is a formal series of trials conducted at sea to
evaluate whether a newly built or significantly upgraded ship meets its
contractual performance specifications before it is delivered to the
customer.

Part of the tests require the submarine to be fully submerged, but the Navy
won't say when submerged tests for the Narwhal will begin.