The 46-metre catamaran would cruise at 12 knots. The company said building would begin early next year and would take 18 months.
Kings Dolphin Cruises & Eco Tours, part of InterCity Group, would operate the new vessel out of Opua in the Bay of Islands.
The company said the modern diesel-electric system for propulsion and power generation, could reduce carbon emissions by up to 60 per cent. Overnight cruises would cost from $349 a person.