A competitor in the laser radial class at the London Olympics, Sara Winther, said the centre would store boats and equipment for athletes who were flatting and had no space.
Mt Albert visitor Graeme Cunningham said the new building should focus more on how the community could use it because it would dominate a public place.
Catherine Steel, of Belmont, said the building looked "futuristic" rather than a boathouse that would fit in with the landscape. Julia Bockett, of Mt Albert, said it looked like a convention centre.
Resident and veteran yachtie and boat designer Jim Young said the centre was a bunker with a carpark on top and would be completely out of character with the surrounding area.
Several hundred people visited the display of drawings for the proposed building, said Yachting New Zealand chief executive David Abercrombie.
Harbour Access trust member John Sandford said suggestions were welcomed in the centre's first public test.