Harbour protection activist Christine Loh Kung-wai yesterday urged pressure groups to apply to rezone the Tamar site so it could not be used to house new government headquarters. Ms Loh, who chairs the Society for Protection of the Harbour, said the group's rezoning applications had failed but it would now offer help to others who wanted to try. 'In many cities, the most valuable piece of land is reserved for the most valuable use. But it isn't necessarily measured by how much money the land can fetch. It is measured by how much the public can enjoy it,' Ms Loh said. Her comments came a day after the Action Group on Protection of the Harbour said it would apply to the Town Planning Board to change Tamar's land use from that of 'government, institution and community' to open space, such as a public garden. 'Whether they [the action group] just target the Tamar site or the entire Central waterfront, they should go to the Town Planning Board,' Ms Loh said. 'I believe if we have five or six groups trying to lower the development density of the Central waterfront, the board will feel the pressure and the public sentiment.' Ms Loh's group previously applied to rezone the Central waterfront development plan by seeking a lowering of development density, but the request was rejected by the board. Meanwhile, the society has organised a photographic competition to raise public awareness of the harbour's changing face. The contest is one of the society's events to mark Harbour Day on November 13. 'We hope the public will have a chance to think deeply about the importance of the harbour and that it will eventually evolve into a community-wide event,' Ms Loh said.