An expanded Opua Marina could bring 60 new jobs and pump an extra $23 million a year into the Bay of Islands economy, the project's backers say.
The marina's second stage, with an extra 149 berths bringing the total close to 400, was formally opened by local hapu Ngati Manu before dawn on Friday.
With the on-water work all but complete, the focus will now turn to creating a public space on reclaimed land and completing an apartment and retail building.
Far North District Council-owned company Far North Holdings (FNH) awarded the $10 million contract to Total Marine Services, a New Zealand firm with a branch in Opua.
FNH chief executive Andy Nock said the marina's first stage, opened in 2000, was a private project and the berths were sold off. That meant none were available to visiting boaties.
"We have 460 international boats coming in each year and clearing customs, then we're turning them away because there are no berths."
Visiting yachties spent on average $30,000 while in New Zealand, Mr Nock said.
The first two piers opened last summer and were 100 per cent occupied, despite being in the middle of a construction site, and the new berths were already fully booked for Christmas.
Local marine businesses had already expanded in anticipation and boat building firm Bluefix had moved from Waipapa to new premises at the marina.
During Friday's opening four pou (carved posts) were blessed along with an anchorstone and a carved touchstone as acknowledgement of Maori history and culture.
The pou were carved by artists Rua Paul, of Paihia, and Renata Tane, of Oromahoe, from totara trees felled to make way for the development. The sailing-related pou are named after Hinemoana (goddess of the ocean), Rongo (god of peace), Tangaroa (god of sea creatures) and Tawhirimatea (god of wind).
Ngati Manu originally opposed the project, staging a series of protests, but has since come on board.
Arapeta Hamilton, a hapu leader, said their primary concern was cleaning up the river but research had shown most pollution originated upstream, not from the marina. The hapu was working with FNH to improve water quality by setting up a nursery, planting trees and working with tourism operators to stop them discharging in the Bay.
Mr Nock put the changed relationship with the hapu down to a willingness to engage on both sides.
"It shows what you can achieve with open dialogue and understanding cultural differences and the views of both parties."
By its fifth year the expansion would inject an extra $23m a year into the economy through longer stays by visiting boaties and more boat repair and maintenance work.
The Opua Business Association expects a 44 per increase in turnover and about 60 new jobs.
A waterfront recreation area including parking, lawns, boardwalks, barbecues, a stage and play area is expected to open by the end of the year. No date has been set for construction of a second apartment and commercial building.
About 100 people attended the pre-dawn opening including contractors, FNH staff, Ngati Manu and Auckland-based Chinese consul Erwen Xu, who was in the Bay of Islands for meetings with the Far North District Council.
Also at the opening was a small group of protesters who held placards and played music during the ceremony. Peter Clark, of Waikino, said his family had lost access to fishing grounds when the marina was expanded.