With Travellift bays accessed through roller doors 11m high and 10m wide, it will allow year-round, under-cover boat building and repairs.
Bluefix is currently based in a shed off Kapiro Rd, north of Kerikeri. It will shift its 10 employees to Opua, take on the five boat-builders who work at Ashby's, and employ up to 15 additional staff.
Bluefix specialises in the design and build of high-end custom sports fishing boats. Its business has expanded dramatically over the past few years with orders for large boats from local and international customers as well as growing demand for refits and repairs.
Director Charlotte Rowe said the move to Opua would give the company more space and direct access to the water.
"Our shed in Kerikeri is now just too small to enable us to meet the orders we have for our NorthCape series of boats and for our refit, repairs and maintenance services," she said.
Bluefix would also expand the services currently offered by Ashby's Boatyard to local and visiting yachties.
FNH chief executive Andy Nock said the merger would take Opua's marine industry to a "completely new level".
"World-class boat-building, repair, maintenance and painting facilities are an important part of our long-term plan for Opua.
The skills and services offered by the expanding Bluefix Boatworks business will complement the new-look, expanded marina and help make the Bay of Islands the upper North Island's destination of choice for boaties."
Construction of the Bluefix facility started last week with 60 truckloads of concrete poured to make the pad. It is due to be completed by Christmas.
Four ageing utility and storage buildings were demolished to make way for the new facility.