But his identity will remain a secret until his sentencing in May.
Also in court was the second officer of the Rena, who pleaded guilty to charges laid under the Maritime Safety and Crimes Act, but entered no plea on a charge laid under the Resource Management Act.
Suppression orders also remain in place over his identity.
The captain was originally charged under section 65 of the Maritime Transport Act with “operating a vessel in a manner causing unnecessary danger or risk” and under the Resource Management Act relating to the “discharge of harmful substances from ships or offshore installations”.
New charges were added in December, including three alleged offences under the Crimes Act and a charge of “willfully attempting to pervert the course of justice”.
Each charge carried a maximum penalty of seven years’ imprisonment.