A New Zealand Defence Force ship has run aground off the Samoan island of Upolu.

HMNZS Manawanui, the Navy's specialist dive and hydrographic vessel, regularly conducts tasks across the Pacific.

Marinetraffic.com's ship tracker showed the vessel was 'aground' near the village of Siumu, on the southern side of Upolu, at 10.45pm Saturday.

Maritime component commander Commodore Shane Arndell said the grounding occurred while conducting a reef survey.

"The safety of personnel is our top priority. All of the 78 who were on board are currently in life rafts and accounted for," Arndell said.

"The New Zealand Defence Force is working closely with the Rescue Coordination Centre who are co-ordinating rescue efforts.

"A Royal New Zealand Air Force P8 has been deployed to assist."

Further updates would be provided as information became available, Arndell said.

HMNZS Manawanui had departed Auckland's Devonport naval base for the Pacific on 29 September.

According to the Defence Force website, the ship has a core crew of 39.

It has been in service since November 2019 and has a top speed of 14 knots (26km/h).

In November 2023, it was used in a seven-week operation to conduct underwater surveys and help to dispose of submerged World War II bombs in Niue, Fiji and Vanuatu.

"Some of our crew hail from Pacific nations and so for them our deployments to the Pacific are a way for them to give something back to their communities," Commanding Officer Yvonne Gray said at the time.