A New Zealand navy vessel hit a reef and sank due to a "series of human errors," a military court of inquiry found on Friday.

The HMNZS Manawanui sank in October while surveying a reef off the coast of Samoa.

The court found that at the time of the incident, "autopilot was not disengaged when it should have been."

Court blames human error

Navy admiral Garin Golding said that the crew misidentified the issue as a "thruster control failure."

"The crew did not realize Manawanui remained in autopilot and, as a consequence, mistakenly believed its failure to respond to direction changes was the result of a thruster control failure," he said.

He added that the ship "started to accelerate toward the reef" rather than changing course.

Golding said that the crew did not check whether the ship was under manual control.

"This check did not occur. Remaining in autopilot resulted in the ship maintaining a course toward land, until grounding and eventually stranding," he said.

He said that the court's finding would be followed by a separate disciplinary process.

What happened to the HMNZS Manawanui?

The HMNZ Manawanui had been dispatched to survey the ocean floor when it ploughed into a reef south of Samoa's most populous island, Upolu, in October.

All 75 crew members and passengers were rescued from the ship, which burst into flames and sank after it struck the reef.

Some sailors suffered minor injuries.

The ship was carrying 950 tons of diesel when it sank. Salvage crews are set to retrieve the fuel, with no major leaks reported.

sdi/zc (AP, AFP, dpa, Reuters)