Some of Auckland's wharves have been found to be too short for cruise ships beyond 300m in length, but Port Otago has already accommodated cruise ships of 311m and 317m at its 420m long Beach St wharf at Port Chalmers.
Chief executive Geoff Plunket said Port Otago had not been approached about hosting any vessels longer than 317m; which is the problem facing Ports of Auckland.
Auckland's Queens Wharf, already in the middle of a $18 million upgrade, is too small for the new generation of bigger cruise ships and may need a $10 million top-up from ratepayers, The New Zealand Herald reported.
Ratepayers and Ports of Auckland are already spending $18.6 million to turn Shed 10 on Queens Wharf into a cruise ship terminal to replace Princes Wharf, which has acted as a temporary terminal for many years.
Mr Plunket said the ''more critical factor'' for Port Chalmers was the sweep of the bend at Harington Pt (not the depth), as opposed to wharf length at Port Chalmers.
Recently granted dredging consents, to possibly deepen the harbour channel for larger container vessels in the future, also allowed for channel widening.
''We have that [consent] flexibility and could decide to widen the channel for a bit of extra comfort,'' Mr Plunket said.
Last year, Port Otago gained 25-year consents from the Otago Regional Council to deepen and widen the shipping channel, between Taiaroa Head and Port Chalmers, but only if larger container vessels indicated they would call on a regular basis.
Port Otago is logged into a port simulator computer in Auckland, and in order to accommodate the more than 300m vessels, their channel passage had been trialled on the simulator before arriving.
Mr Plunket said while on a ''perfect day'', the sweep of the Harington Pt bend could accommodate larger vessels, is was recognised that their ''operating parameters could be constrained'' by the effects of wind and tide.
Waterfront Auckland and the ports company have commissioned engineering consultancy firm Beca to look into bigger cruise ships, more than 300m long and which carry more than 3000 passengers.
Cruise New Zealand chairman Craig Harris told the Herald the widening of the Panama Canal next year and increasing demand for cruises by China was leading to bigger ships of 3500 to 4000 passengers in the South Pacific.
Already, 15% of cruise ship visits to Auckland this season were too big for Queens Wharf and the figure would keep growing, he said.
''Our problem is we are trying to create certainty for the cruise lines and it is hard because these guys are scheduling two, three years ahead.
''If we don't make decisions we are in danger of the cruise lines bypassing us,'' Mr Harris said.
• At the Port of Tauranga, the first vessel to use its new $30 million wharf extension at Sulphur Point arrived off-loading a new ship-to-shore crane, the port's sixth terminal crane.
The 170m wharf extension, due for completion at the end of March, is a major part of the $180 million capital developments programme.
It increases the length of continuous quay at Sulphur Point to 770m.
Twenty years ago, the average vessel length calling at Tauranga was 180m; the average is now 230m, with the longest regular caller at 269m.
