HMNZS Manawanui is in water about 30m deep and a light oil sheen from its initial capsize is being dispersed by wind and waves, Maritime Component Commander Commodore Shane Arndell says.

Royal New Zealand Navy (RNZN) divers were on the water at first light today to assess the wreckage of the ship, which ran on to a reef south of Upolu on Saturday night and sunk on Sunday morning.

“The dive team has begun assessing the area where HMNZS Manawanui sank to better understand the environmental impacts and clean-up efforts required in Samoa,” Commodore Arndell said.

A number of government agencies are involved in supporting the Samoan Government’s response to the incident, Experts from Maritime New Zealand and other agencies are also assisting with understanding the environmental impacts and initiating clean-up actions.

Wildlife experts from Massey University have been assisting with the response and the New Zealand Defence Force, which has 28 personnel in Samoa, is working closely with the Samoan Government.

A range of equipment was sent to Samoa with New Zealand Defence Force personnel to assist with the initial response and help address environmental impacts to the area.

Equipment includes remotely operated vehicles used to establish the debris field, and also Maritime NZ spill response equipment, which can be used both in the water and on the land.

“Our personnel have begun clearing flotsam from the beach area and environmental assessments and clean up activities are under way,” Commodore Arndell said.

“A light oil sheen from the ship’s initial capsizing is being dispersed by wind and waves.”

Maritime NZ responders are working closely with Samoan authorities, and NZDF personnel on the ground, to develop plans around how to support the environmental response.

The Royal Navy’s HMS Tamar is helping provide security and logistical support in the immediate area.

“As more information is gathered from the responders on the ground, NZDF will bring further equipment from New Zealand to support the response,’’ Commodore Arndell said.

The site of the sunken vessel – which is lying about 30m deep - had been declared a “prohibited area” by Samoan officials.

Late on Monday night, 72 of the 75 crew and passengers rescued from Manawanui arrived back in New Zealand on board a RNZAF C-130J Hercules.

They were being provided welfare support and were re-uniting with families this afternoon.

The three other members from another government agency were due to return today on a commercial flight.

HMNZS Manawanui Commanding Officer Commander Yvonne Gray said the incident was when her “very worst imagining became a reality”.

“However, my team responded in exactly the way I needed them to. They acted with commitment, with comradeship and, above all, with courage.”