Some predict it could herald a jobs bonanza for the area around Ardersier on the Moray Firth.
The Port of Ardersier's chief executive, Captain Steve Gobbi, said the green light from the Scottish Government and regulators Marine Scotland and Transport Scotland was a "major milestone" for the 400-acre facility.
He said: "There are few, if any, vacant sites of this scale in the northern North Sea offering deep water access and the potential to undertake manufacturing, assembly, operations, maintenance and decommissioning from a single location. We now have the all-clear to commence site works and undertake major dredging which will see the port open for business next year."
Scottish Natural Heritage opposed the plans because of the yard's proximity to protected sites, such as the Inner Moray Firth Special Protection Area and the Moray Firth Special Area of Conservation, but mitigation measures have been agreed.
The yard once housed the McDermott fabrication yard which built oil rigs and at its peak in the 1970s employed more than 3,000 people.