Ambulances took 17 people, including a crew member, away for treatment for injuries ranging from a head gash to a suspected broken arm.
Six went to North Shore Hospital and the rest to a Takapuna accident clinic as the ferry was left with a huge gash through its above-hull bulwark and into its outside bow deck.
Passengers spoken to at the time blamed the number of injuries on unsecured seating aboard the vessel, which was reflected in court documents.
Fullers allegedly failed to ensure seats were sufficiently stable "that it would not harm passengers if the vessel stopped suddenly, moved significantly or impacted another object".
Charge sheets attribute the accident to the Kea's "digital control system".
One of the particulars of the charge included: "failing to take the vessel out of service until the faults in the control system were fixed".
It is alleged Fullers adopted "risk-mitigation procedures" three months before the crash, which meant manual controls were to be used until the control system was fixed.
They were allegedly not followed.
Fullers was also accused of failing to ensure the vessel's skippers were sufficiently competent in the operation of the system and the procedures in place to deal with its malfunctioning.
Jonathan Kiygan, a manager at Safety at Sea, had worked as a yacht captain and explained how a ferry's digital control system worked.
"From the screen, you can monitor all the systems of the ship - electrical supply, engine, alarms, smoke detectors - everything is centralised in one system," he said.
He said ferries could be operated manually but it was easier with the aid of the electronic system: "like a video game".
Belmont resident Judy Rhodes was aboard the Kea at the time of the crash and was still undergoing physio for her wrist.
She was surprised to hear the allegations about defective digital systems on the ferry.
"You put your life in their hands and trust them to do the job they're supposed to do," she said.
"If you've got a faulty car, would you drive it?"
Lawyer Fletcher Pilditch said when dealing with health-and-safety breaches, the court looked at a variety of elements including the extent of the failure and the outcome of the offending.
"In some cases the breach can be quite a fine one - in hindsight they know they should have done things differently," he said.
"Or at the other end you can have a company that's not complying with its own policies, doesn't care about having a policy, hasn't educated any of their staff around issues that give rise to safety concerns and you could view the breach as quite flagrant."
Mr Pilditch said though the charges were criminal, those brought before the court had rarely set out to cause harm.
"You're dealing with people who own businesses or run businesses who actually do want to ensure people . . . are safe and unharmed," he said.
Fullers chief executive Doug Hudson said he could not comment on the case while it was before the court but stressed they had complied with Maritime NZ.
The Kea had been repaired and been back in service since the end of July.
Maritime NZ prosecutions
2011-12: 14
2012-13: 13
2013-14: 11
2014-15: 11
