Mātai means to observe, investigate and examine, and connects to the mahi (work) of protecting New Zealand's fisheries resources.
MPI Regional Fisheries compliance manager Tyrone Robinson said: "Our shared fisheries are important to many communities and this new vessel means we'll be even more visible.
"Everyone's got a part to play in protecting our resources and we encourage people who witness suspicious fishing behaviour to contact us."
He said Mātai is a versatile vessel, able to be launched from the beach and able to patrol and quickly respond to a range of situations at sea.
Meanwhile, long-serving MPI vessel the Kāhutara, which is about 20 years old, is being repurposed by the Customary Fisheries Forum, Mai Paritu tae atu ki Turākirae, to support Tangata Kaitiaki fisheries management efforts.
"We're really pleased that the Kāhutara, which has served us well, will continue to be used for important work by the Tangata Kaitiaki for sustainable fisheries management,' Robinson said.
Mai Paritu tae atu ki Turākirae chairman Paul Ratapu was at the karakia and praised the MPI compliance team together with Sandra Mauger and Harataki Manihera Fisheries New Zealande efforts to create meaningful relationships with Ahi kaa, with respect to their endorsement of mana whenua o Ahuriri with the launch's tikanga, and ongoing support of Tangata Kaitiaki efforts on the coastline through the Kāhutara vessel.
"It's an exemplar for a respectful and productive Crown and Tangata Whenua relationship," he said. "Ka mau te wehi!"