HMNZS Manawanui was a dive and hydrographic vessel of the Royal New Zealand Navy (RNZN). It had previously served as the civilian survey vessel MV Edda Fonn in the Norwegian oil and gas industry. The ship was purchased for the RNZN in 2018, and commissioned on 7 June 2019, replacing the hydrographic survey ship and diving support vessel .
Manawanui entered operational service in early 2020 and undertook multiple deployments in the Pacific over subsequent years, participating in RIMPAC 2020 and supporting operations in the aftermath of Cyclone Gabrielle in 2023.
Manawanui sank on 6 October 2024 after running aground while surveying a reef off the coast of Samoa. All 75 people on board Manawanui were rescued. In late November 2024, the first report from the naval inquiry into the Manawanui sinking attributed the sinking to human error. In early April 2025, the naval inquiry's final report concluded that the sinking was the result of human error. Following a disciplinary investigation, charges were laid against three naval officers, including her former captain, in February 2026.
Civil career and conversion
The ship was built in 2003 by Myklebust Verft and delivered in May as MV Edda Fonn to Østensjø Rederi to serve as a survey vessel for work in the oil and gas industry. It was based in Haugesund, Norway. Edda Fonn was chartered out to the Norwegian subsea service provider Reach Subsea in December 2014, completing survey and inspection tasks in the North Sea. In February 2017 the ship was tasked with inspecting pipelines in the Mediterranean Sea between Algeria and Spain.
In August 2018 Edda Fonn was purchased by the Royal New Zealand Navy (RNZN) at a cost of $103 million to replace the hydrographic support ship and the diving support vessel . The New Zealand government had originally planned to purchase a newly built ship for these roles, with work on this project beginning in 2013. After NZ$148 million of funding for the project was diverted in 2017 to cover the unexpectedly high costs of upgrading the RNZN's two s it was decided to acquire a second-hand vessel instead. New Zealand Ministry of Defence officials reviewed 150 vessels before identifying Edda Fonn as suitable for conversion.
Edda Fonn underwent initial work at Orskov Yard in Frederikshavn, Denmark. The moonpool and remotely operated underwater vehicle hangar were remodelled, and specialist equipment including a multibeam echosounder, diving launch and recovery system, and davits were installed. It was also repainted in RNZN colours.
Operational history The ship arrived in New Zealand in May 2019. Renamed, HMNZS Manawanui was commissioned into the RNZN on 7 June. Prime Minister Jacinda Ardern was the ship's sponsor. At the time of commissioning it was intended that the ship would serve with the navy for 15 years. Manawanui was based at the Devonport Naval Base. Its honorary home port was Gisborne. The ship's first commanding officer was Lieutenant Commander Andy Mahoney.
After being commissioned, Manawanui required further modifications to be fitted with communications equipment and items specific to a military role. These works were originally scheduled to be completed by November 2019 but were delayed due to technical problems and the impact of the COVID-19 pandemic. The inability of foreign contractors to travel to New Zealand during the pandemic was one of the causes of the delays. Bad weather and difficulties with fitting new equipment to the ship also contributed. Most of the modifications had been made by mid-2020 but the project was not completed until September 2023. Manawanui was able to be used for much of this period, with new capabilities being added as elements of the modifications were completed.
Manawanui completed its initial safety and readiness checks in February 2020. It received interim operational release that month, which was earlier than the initially planned date of April 2021. This change was made to allow the ship to participate in that year's RIMPAC military exercise off Hawaii. Manawanui took part in this exercise during August 2020. During the exercise Manawanui operated with warships from Australia, Brunei and Singapore. As a result of COVID-19 restrictions its crew was unable to disembark the ship during the deployment.
During 2021 Manawanui received a range of modifications and two new engines. These works were delayed by the strict COVID-19 lockdown in Auckland that year. Sea trials were undertaken in March 2022.
In September 2022 Manawanui was part of a multinational operation to remove World War II ordnance in Tuvalu. On 9 December 2022, Commander Yvonne Gray took the command of Manawanui. Gray, originally an officer in the Royal Navy of the United Kingdom, moved to New Zealand in 2012.
During February 2023 Manawanui provided support to the area around Gisborne in New Zealand in the aftermath of Cyclone Gabrielle. This included assessing damage to Gisborne's port and transporting supplies. During the same month the ship was used to carry 3.2 tonnes of cocaine to New Zealand after it was seized by the police during an operation in which the drugs were intercepted after they had been dropped in the Pacific Ocean ahead of being smuggled into Australia. In November 2023 it conducted undersea surveys and disposal of World War II bombs in Niue, Fiji, and Vanuatu.
In 2024 the vessel carried out three deployments to the South West Pacific, including visits to Kermadec Islands, Samoa, Tokelau and Niue. In its final deployment the vessel sailed from Devonport on 28 September, intending to return to port on 1 November.
Sinking Loss On the evening of 5 October 2024 Manawanui ran aground around off Siumu, on the south coast of Upolu island, Samoa, whilst carrying out survey work of a reef in rough seas and high winds. Commander Yvonne Gray gave the order for everyone to abandon the ship. All 75 crew on board were evacuated by four of the vessel's life rafts and two rigid hull inflatable boats early on 6 October. Rescue efforts were managed by the New Zealand Rescue Coordination Centre and the Royal New Zealand Air Force deployed a Boeing P-8A Poseidon aircraft to assist. The evacuation began at 7:52 p.m. on 5 October. Due to challenging weather conditions it took five hours for the lifeboats to reach the shore. One of the rescue boats flipped over during the journey and its occupants walked to shore via the reef. At 10:00 p.m., the British cruise ship MS Queen Elizabeth and Danish cable-laying ship MS Lodbrog responding to the mayday arrived on scene to render aid.
The vessel caught fire by 6:40 a.m. on 6 October and capsized and sank by 9:00 a.m. At least 17 people were injured in the incident, many from cuts and abrasions from walking on the reef, and three received hospital treatment, including one for a dislocated shoulder. The crew and passengers, including seven scientists and four personnel from foreign militaries, were accommodated in Samoa before being flown to New Zealand. The RNZN was carrying out works to salvage the vessel and mitigate the environmental impact of the sinking. On 7 October local residents reported seeing and smelling oil near the wreck. The acting Samoan Prime Minister Tuala Iosefo Ponifasio said in a press statement, "HMNZS Manawanui is not recoverable and has sunk into the ocean."
The vessel is the first New Zealand naval vessel to be unintentionally sunk since World War II and the first to be lost in peacetime.
Timeline
Friday 4 October 2024
22:00- Survey of Sinalei Reef commences.
Saturday 5 October 2024
18:11:13- Ship alters course to 340° in manual control.
18:13:08- Ship placed into autopilot.
18:14:47- Helm attempts course alteration to starboard. Ship fails to alter course.
18:15:20- ECDIS alarm heard.
18:15:29-18:15:53- Increased demand on angle and power of thrusters.
18:15:57- Helm announces "no steering to starboard".
18:16:18- Helm announces “it’s not really doing what I want it to do.”
18:16:18-18:16:43- Crewmembers attempt to control the ship, again announcing "it's not really doing what I want it to do."
18:16:55 Captain called to the bridge.
18:17:18- "Nautical Emergency" piped.
18:17:20- Captain arrives on bridge.
18:17:21-18:17:59- Crew continue to attempt to retake control of the ship.
18:17:59- Ship runs aground on the reef.
18:18:37- Emergency stations piped. Searches throughout the ship for damage and injuries commence.
18:18:49- Machinery Breakdown piped.
18:18:55-18:25:10- Crew search the ship, engineers close up and discussions continue on bridge about how to take control of the ship.
18:25:39- Searches complete.
18:27:34- Discussion about “do you want to take it out of auto now?”
18:27:43- Propulsion control regained, control switched from auto to manual.
18:28:00-18:42:40- Crew continues to attempt to stabilise the ship. Further grounding noises heard at 18:32:06.
18:43:20- Mayday call made.
18:46:45- Captain pipes to prepare to abandon ship.
18:48:40- “Hands to liferaft stations, Hands to liferaft stations.” piped.
18:48:55- Captain pipes crew to tell them to prepare for their time in the liferafts, by wearing extra clothing and using the toilet.
18:50:00-18:50:10- Captain expedites the abandon ship due to the increasing roll of the ship.
18:54:20- Captain orders lifeboats to be launched.
18:55:00- Ship abandoned.
Sunday 6 October 2024
~06:40- Fire begins on stricken ship.
~09:00- Ship capsizes and sinks.
Impact At the time of the sinking, Manawanui was carrying 950 tonnes of diesel fuel. On 8 October local Samoan residents reported that the sinking caused an oil spill which threatened tourism and fishing in the local area. On the same day, the RNZN stated that while oil had leaked from Manawanui as it sank naval divers who had inspected the wreck had not detected anything leaking from it. The Samoan Government concurred with this assessment. At this time the wreck was below the surface, with the ship lying on its side. The RNZN was considering options to remove fuels and other chemicals from the wreck. On 11 October local fishers reported fish covered in oil, and Samoan authorities confirmed a leak of of diesel and damage to the reef. The crew of a RNZAF Poseidon who overflew the wreck on this day also sighted a slick. RNZN divers determined that there was a leak emanating from the ship's engine room.
Local Samoan residents expressed concerns about the impact of the ship's sinking on the maritime environment, and called for compensation and an independent inquiry. Tafitoala village representative Taloaileono Vasasou said that the oil leak was polluting the coast and contaminating their clam reserve while the senior matai (chief) of Vaiee village Tuia Paepae Letoa reported that fish caught in the area were covered with oil. Residents of the Safata district convened a meeting to discuss the impact of the sinking and demand compensation. Due to the sinking, a stretch of coastal area near the wreckage site was closed to fishing on 7 October. Tafitoala matai and fisherman Afoa Patolo Afoa said that the sinking and resulting fishing ban would affect the livelihoods of many local residents.
In late November 2024 former Samoan Member of Parliament Tuia Pu'a Leota told Radio New Zealand that food supplies in the local district were low and called on both the Samoan and New Zealand governments to provide local communities with more information. He said that the impact of the ship's sinking was devastating for local villagers who depended on fishing for food and income.