Environmentalists and experts from Auckland University have joined forces to try to reduce the incidence of ships hitting whales in the Hauraki Gulf.
The gulf is home to a pod of up to 50 endangered Bryde's Whales.
The Environmental Defence Society says an average of two whales a year die after being hit by ships.
The society, the Hauraki Gulf Forum and the university are working with Department of Conservation officials and local councils on ways to reduce such deaths.
DOC's Auckland Conservator, Sean Goddard, says fresh research shows the whales spend most of their time less than 12 metres below the waters of the gulf, which explains why they are so vulnerable to being hit by large ships.