The Transport Accident Investigation Commission has opened an inquiry into the loss of power experienced by the Interislander ferry yesterday, which led to the vessel issuing a mayday call in the Cook Strait.

The ferry lost its power around 5pm, with around 800 passengers and 80 crew on board. It eventually got power back and made a slow journey to Wellington, where it arrived after 9pm, followed by tug boats for precaution.

The chief investigator of accidents, Naveen Kozhuppakalam, is appealing for ferry passengers and residents of Wellington’s South Coast who have videos or photographs of the events to contact TAIC at [email protected].

“At about 5pm, the vessel was in the Cook Strait off Wellington’s South Coast when it suffered a main engine failure and loss of propulsion,” Kozhuppakalam said.

 “The vessel dropped anchor and onboard engineers began repair work. Power was restored about two hours later. The vessel, escorted by two tugs, proceeded to Wellington without further incident.”

A team of investigators with expertise in marine operations, engineering and maintenance will now look into what caused the incident.

Their initial investigation work will be to interview the ship’s crew, incident responders, Wellington harbour authorities, and other witnesses.

The Commission will also inspect the ship and obtain all relevant records and electronic recorded data.

TAIC opens this type of inquiry when it believes the circumstances of an accident or incident have - or are likely to have - significant implications for transport safety, or when the inquiry may allow the Commission to make findings or recommendations to improve transport safety.

KiwiRail also said yesterday that will investigate the cause of the temporary loss of power.

• Interislander ferry loses power in Cook Strait, declares mayday

The AIS ship tracker showed several vessels rushing to the Kaitaki’s aid yesterday afternoon after the vessel dropped anchor and issued a mayday call.

The AIS ship tracker shows the ferry was in a difficult spot with several vessels rushing to its aid. Image / Screenshot