Firefighters prevented a luxury yacht from sinking at Auckland's Viaduct this morning.

The vessel was moored off the southern side of Te Wero Island when the Harbourmaster notified emergency services it was taking on water.

Fire Service spokesman Tony McDonald says the 22 metre yacht boat was badly damaged way when firefighters reached it when the bow just centimetres away from going under the water. Portable pumps were used to empty the boat of water.