Wellington Harbour contains an area of about 20,000 acres, having depths varying from 6 to 14 fathoms. The entrance varies from 7 to 8 fathoms with a deep-water channel 1,000 ft wide. The current never exceeds 2½ knots and the tide varies from 2 ft 6 in. to 4 ft 6 in.

The harbour board has 10 wharves directly alongside the city business centre, with total lineal berthage of 23,616 ft and with depths alongside varying from 16 ft to 41 ft; 8,481 ft of berthage is linked up with the national railway system. There are seven other wharves in the harbour with 3,712 ft lineal berthage. Miramar (coal) and Burnham (oil) wharves are in Evans Bay, and the Point Howard (oil) wharf is at the northern end of the harbour. Overseas berths are generally served with four to six electric cranes per berth. There are 33 cargo stores with capacity of approximately 64,000 tons and all are equipped with overhead lifting gear with capacities of from 30 cwt to 5 tons. A coal berth has six 4½-ton grabbing cranes for delivery of coal to road and rail transport through four 60-ton self-propelling hoppers. One fixed 10-ton hydraulic crane and a floating crane with lifting capacity of up to 80 tons are available for heavy lifts. There is a floating dock with lifting capacity of 17,000 tons. Two privately owned tugs are available at the port.

More than half of New Zealand trans-shipment trade takes place at Wellington mainly on account of its geographical location.