"Local board members share serious concerns about the impact of a marina on the Putiki Bay environment and its potential for compromising future increased commercial and community use of what is quite limited public land in the immediate vicinity," a board statement said.
Kennedy Point Marina said the new scheme was not only smaller. But an entirely different marina system was planned to be built and a road would be widened to ease congestion.
"The company has agreed to widen Donald Bruce Rd to provide a full through-lane to the ferry terminal," a statement said.
Discussions are also being held with Auckland Transport about upgrading the existing car park at the marina, used by ferries from the Wynyard Quarter and Half Moon Bay.
Kennedy Point Marina has had more than 500 expressions of interest for berths and 68 per cent of those are Waiheke ratepayers, it said. That proved huge demand existed.
Tony Mair, a Kennedy Point Marina director, explained more.
"The advantages of using floating attenuators are considerable, including minor impact on the seabed compared with a rock breakwater and a much quicker and easier installation.
"All units will be shipped from Sweden. Each pontoon weighing 115 tonnes will be towed into position. Another significant benefit of the new design will be public access for viewing and fishing from one of the attenuators, which wasn't possible with the rock design. Floating attenuators also leave the marina basin open to tidal flows and currents," he said.
"The changes address some of the concerns raised by the local board and some local submitters with the size and visual impact of the original design, although he does not anticipate they will appease the vocal anti-marina group, Save Kennedy Point Inc, that established to oppose the development," Mair said.
Save Kennedy Point Inc says: "We are simply a bunch of local Waiheke Islanders who care about this Island and believe that Kennedy Point and the wider Putiki and Anzac Bay areas have significant ecological, landscape and recreational values that need to be protected and restored.
"We are still in our infancy and have now suddenly found ourselves up against our first big challenge which is opposing the proposed marina at Kennedy Point."
The Kennedy Point Marina statement said a hearing into the revised proposal was due to be held in April.