Interislander ferry Aratere ran aground after a button was “inadvertently pressed”, sending the vessel off-course, according to an internal safety bulletin obtained by 1News.

According to the bulletin, dated July 5, the bridge crew had switched the Aratere from hand steering to autopilot as it passed Mabel Island when an “execute button was inadvertently pressed” at 9.26pm.

This led the vessel to “commence an alteration of course” by around 1 nautical mile earlier than planned.

The bridge team attempted to switch back to hand steering mode but was unable to override the autopilot in time.

The crew was able to regain control one minute later “however it was too late and the vessel ran aground in Titoki Bay”.

The bulletin instructed a number of restrictions were on place over the use of autopilot, with hand steering to be instead used in certain, specified situations.

“Autopilot functionality is to be used with caution — especially within enclosed waters or areas of high traffic density.”

It continued: “The accident and early operation of the execute button on the starboard multipilot commenced a chain of events which led to the grounding.

“The reasons why recovery controls (defences) that should have corrected this unplanned deviation were unsuccessful is part of the ongoing investigation.”

Gradual return to service

Maritime New Zealand lifted its detention notice this evening, allowing the Aratere to gradually return to service under “imposed conditions”.

The ferry has been in Picton under the notice since it ran aground shortly after leaving the port on the evening of June 21 following what was believed to have been a steering failure.

“Earlier this week, we inspected the vessel, and observed it undertake several tests while at berth involving systems, processes, and equipment,” Maritime NZ director Kirstie Hewlett said today in an update.

Three investigations are looking at what happened to the vessel when it hit the coastline near Picton.

“Off the back of these tests we have now lifted the detention notice, but imposed conditions on the operation of the vessel.”

The conditions would allow the Aratere to return to service “through a graduated and controlled approach that enables further assurance by KiwiRail, any corrective and preventative measures are implemented, and the vessel is operating safely”.

“Initially, the conditions will allow crew and rail freight only (four return sailings), then trucks and their drivers, followed by a limited passenger service, and then full capacity sailings to be permitted,” she said.

“The full return to service is subject to KiwiRail demonstrating it has implemented its return to service plan, and no further issues have been identified.”

Harbourmasters in Wellington and Marlborough have also placed conditions around pilotage for the Aratere’s exit and entry of the two harbours.

Maritime NZ would carry out a comprehensive audit of the Interislander fleet and its training, risk management, and procedures in the coming weeks.

“Maritime NZ’s inspections and audits are a reflection of a point in time, and the operator, KiwiRail has the primary responsibility for day-to-day safe operation of the vessel, and its wider fleet,” Hewlett said.

A Maritime NZ investigation into the range of factors behind the Aratere’s grounding – which is separate from the detention notice and audit – is expected to take several months.

Coffee break theory dismissed

Hewlett denied New Zealand First’s query as to whether the Aratere ran aground after someone onboard the vessel “put the autopilot on, went for a coffee, and then couldn’t turn the autopilot off” when they returned.

“While the cause of the grounding is yet to be formally determined, Maritime NZ’s preliminary enquiries have found that the incident was not due to a crew member leaving the bridge to make a coffee,” she said.

The Aratere was next due to sail from Picton to Wellington tomorrow.