Organisers say a flotilla of more than 40 boats sailed to the King Salmon marine farm at Ruakaka Bay on Saturday to protest against the company's proposed development of eight new sites in the Marlborough Sounds.
The Guardians of the Sounds group says if allowed to go ahead, the fish farm expansion will trigger a gold rush of applications that will be catastrophic for the Sounds.
Chairperson Peter Beech says locals have been left out of consultation over the proposal and the protest is aimed at the Government, the Ministry of Fisheries and local MP Nick Smith.
Mr Beech says Sounds residents want the Government to understand their strong opposition to their neighbourhood being turned into an industrialised zone.
Locals are also very worried about pollution of the waters by so many farms, he says.