The interim report from New Zealand Court of Inquiry has revealed that human error led to the grounding and sinking of HMNZS Manawanui off the coast of Samoa.
The incident occurred during survey operations in October 2024.
HMNZS Manawanui is the Royal New Zealand Navy's specialist dive and hydrographic vessel, capable of conducting various tasks across the South West Pacific.
Chief of Navy Garin Golding initiated a Court of Inquiry to ascertain the facts surrounding the incident.
The inquiry aims to uncover the reasons behind the grounding and to determine lessons for the future.
The final report is expected in the first quarter of 2025, following an investigation.
The report identified human error as the primary cause, necessitating a separate disciplinary process after the inquiry concludes.
Several contributing factors will be examined in detail during the second phase of the inquiry.
During the survey, the ship's crew attempted a routine starboard turn within the survey area, initially setting a course of 340 degrees.
However, the ship failed to respond as intended when turning towards an easterly course.
Consequently, Manawanui left the approved survey area, accelerating towards the reef and grounding at over 10 knots.
The ship travelled approximately 635 metres before becoming stranded, grounding multiple times.
Full control of the propulsion system was regained after ten minutes, when the autopilot was disengaged.
The inability to turn and stop the ship was attributed to the autopilot mode, which hindered manual manoeuvres.
Efforts to manoeuvre the ship off the reef were unsuccessful. Emergency stations were activated, and damage assessments were conducted.
Garin Golding said: “To provide some immediate assurance, we have conducted a series of audits in the Fleet and looked to implement initial lessons identified from the interim report around training, risk management, and improving relevant orders, instructions and procedures.”
The Transport Accident Investigation Committee, the Royal Australian Navy, and the Royal New Zealand Air Force supported the inquiry, using evidence from crew interviews, expert witnesses, and ship recordings to determine the primary cause.
