There was no warning for passengers to brace and bench seating toppled forward, injuring people.
"The commission found that it was about as likely as not that the master lost control of the starboard propulsion system because he did not fully press the 'give-away' button on the centre console before taking control at the wing console," the report said.
The commission found the master had not been sufficiently trained in the new control system and Fullers knew there were faults with it, as it sometimes did not respond properly - it was recommended these deficiencies be fixed.
Fullers should also consider securing passenger seating, the report said.
In May, Fullers was fined $140,000 in Auckland District Court for failing to take all practicable steps to ensure that no action or inaction of any employee harmed another person.
- NZN