Each port had its own characteristics, but they can be divided into three broad categories: major ports, river ports and breakwater ports.
Auckland, Wellington and Lyttelton were safe natural anchorages and required little improvement. The people who administered these large ports squabbled and struggled from time to time, but all followed the same process of reclaiming land, and building wharves and slipways or dry docks. All three ports did enough business to keep up with the growth in ship size, which seldom exceeded 1,500 tons until the early 1880s, then soared to 5,000–6,000 tons, and by the early 1900s exceeded 10,000 tons in a few cases.
Otago, the other major port, had greater problems, but managed to keep up with its competitors. It could never decide whether it wanted the big ships up at its city wharves or at nearby Port Chalmers, where the deep water ran out. In 1881, after much controversy, it opened ‘The Big Ditch’, Victoria Channel, which it continued to deepen over time.
River ports were very common. River mouths gave some natural shelter and they could be improved if communities were willing to pay for dredging and training walls. Unfortunately New Zealand’s mountain-fed rivers are short, shallow and dangerous. Only the Waikato, Whanganui and Clutha were navigable inland for any real distance and all rivers concealed real dangers. Shifting, submerged sandbars guarded entrances, and many river mouths moved, cutting fresh entrances after heavy storms. In the river itself there were snags, shallows and other hazards. The more significant river ports are on the west of the country – Greymouth and Westport in the South Island, and Whanganui in the North.
Hokitika was a very colourful river port. Despite its dangerous entrance and the snags that infested the river, it sprang into life in 1864 when gold was found nearby. The Canterbury provincial government, desperate for revenue, declared it a port of entry the next year, and by 1866 Gibson Quay was usually crowded with small ships – or at least those that had survived the ordeal of entering port. Between 1865 and 1867 there were 108 strandings – one every 10 days – 32 of which were total wrecks. Hokitika Harbour limped on long after the gold ran out, but its trade dwindled and it was closed in 1954.
Only a few river ports could handle ships over 200–300 tons and many were abandoned, caught between rising ship sizes on one hand, and by silting (often caused by upstream bush clearance) on the other. The last small river ports, Whakatāne, Pātea, Kaiapoi, Blenheim, Motueka and Māpua, closed between the late 1950s and the mid-1970s, undermined by road and rail competition. Whanganui limped on, but in the 2010s only the physically isolated river ports still handled much traffic, notably Gisborne (which developed as a hybrid river–breakwater port).
The river ports had their shortcomings, but at least they offered some natural protection. It was even harder for settlements that tried to set down roots on completely exposed beaches. The open roadstead ports, as they were called, included Ōamaru, Timaru, New Plymouth and Napier. In their early days they offered virtually no shelter and could be made safe only by building massive artificial harbours protected by breakwaters and causeways.
The cost worried many. It was not until the interwar years that Napier people finished their breakwater port, ending the days of transferring cargo from big ships out in the bay. Much earlier, even Ōamaru and Timaru people had looked at cheaper options – the shallow creek in Ōamaru’s case, and Milford Lagoon at Timaru.
When the town of Ōamaru sprang up to serve the new pastoral runs in the 1850s, it depended on surf boats. The town boomed in the 1860s, but the provincial authorities built only an exposed jetty, which was swept away in a storm in February 1868 along with the ships Star of Tasmania, Water Nymph and Otago. Ōamaru became a shipwreck black spot, claiming over 22 total wrecks between 1862 and 1875. A harbour board was formed in 1874, and work began on a 600-metre breakwater. By 1876 construction had advanced far enough to shelter large steamers. The days of shipwrecks were virtually over at Ōamaru, which had built four wharves by the time the sheltering breakwater and causeway were finished in 1884.
Ōamaru port closed in 1974, but in general the breakwater ports have fared better than the river ports. In the 2010s large ships still used Timaru, New Plymouth and Napier.