At a trial at Wellington District Court last month, Cardno denied all charges against him, which the Crown said were carried out in the early 2000s in Martinborough.
During the trial the defence's case was that nothing sexual had ever happened and the complainants had invented the story because of problems they were having in their lives at the time the alleged offences took place.
The defence had also challenged the reliability of the complainants' evidence.
During the trial Cardno denied all the allegations and told the court he was in a relationship when the offences took place.
The Crown said the complainants "had not put their heads together, colluded and made false allegations".
Today, Judge Tompkins said that Cardno's actions had a "devastating effect" on his "vulnerable" victims.
He said Cardno seemed to have no "remorse or insight" into his offendings.
