Three senior Royal New Zealand Navy officers, including the commanding officer, have been charged over the loss of HMNZS Manawanui after the ship struck a reef off Samoa.

The charges have been laid under the Armed Forces Discipline Act 1971, alleging errors on the bridge on the evening of October 5, 2024, led to the vessel grounding on a known navigational hazard southwest of Tafitoala village on Upolu Island.

Commander Yvonne Gray, Lieutenant Commander Matthew Gajzago and a third officer will face court martial over the sinking of the ship.

Commander Yvonne Gray has been charged over the sinking of HMNZS Manawanui. Photo / NZ Defence Force

Pleas have not yet been entered over the allegations, although Gray has indicated via her lawyer that she will defend the charges.

The charging documents include the allegation that the third person, the officer of the watch at the time, was guilty of “negligently causing a ship to be lost”.

The charge sheet alleges they turned Manawanui towards a reef that lay about half a nautical mile ahead, at about 6.13pm local time, while travelling at more than four knots.

They are also accused of failing to disengage autopilot and take manual control in time to prevent the grounding.

Gajzago, who was the command supervisor on the bridge, has been charged with “negligently permitting a ship to be lost”. It is alleged he failed to properly supervise third officer and ensure the ship avoided the reef.

Gray faces two alternate charges relating to the moment the ship approached the hazard. One alleges she negligently permitted the ship to be lost, by being absent from the bridge while within a nautical mile of a known reef. The alternate charge, which could be pursued instead, alleges she failed to attend her place of duty on the bridge in those circumstances.

Gray also faces a separate charge alleging she failed to ensure an appropriate plan was in place to manage the risks of conducting hydrographic survey work in uncharted waters close to reefs south of Upolu.

The charges were certified for trial and laid earlier today.

The sinking of the Manawanui was one of the most serious peacetime incidents in the modern history of the Royal New Zealand Navy. It has proved embarrassing for NZDF and the Navy, and expensive at about $120 million, which includes the cost of the ship and the clean-up.