Cruise ships face new restrictions in Fiordland this summer because of concerns about their impact on some of this country's most beautiful spots.
The operator of the biggest ships to visit New Zealand waters says the new rules mean cruise lines will have to work with each other to stagger arrivals in places such as Milford Sound.
Environment Southland has imposed the limit — two ships in any waterway, passage, fjord, bay or inlet — because of fears that the growth of cruising will be unsustainable.
This summer 132 cruise ships are expected to visit southern New Zealand.
"It is clear that unrestrained growth of the cruise ship industry in Fiordland is unsustainable," said director of policy, planning and regulatory service, Vin Smith.
"We anticipate the limit will help to protect Fiordland's outstanding natural character and landscapes, which have intrinsic and cultural value, as well as being part of why both New Zealanders and international tourists want to visit."
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Royal Caribbean is bringing back one of the world's biggest ships, the 347m long Ovation of the Seas, this summer and it will include visits to the fjords.
The company's managing director for Australia and New Zealand, Gavin Smith, said it was working with regulators and governments around the world to prove it was a responsible operator.
He said the new rules shouldn't affect operations too much as there were not often three or more vessels in the one area at the same time.
"It's not that prevalent — what we are moving through at the moment is staggering arrival and departure times through the sounds," said Smith.
Most ships would be in Milford Sound for two to three hours but they were highly visible.
"The challenge for regulators is to get ahead of it. All we want from regulators is plenty of notice so we can deliver on what we promise." Cruises are booked further ahead than most holidays.
He said discharge coming from funnels was often steam from "scrubbing" sulphur rather than smoke, but had sparked concern.
"The scrubbers can generate white steam so they're a more visible emission even though it's sulphur-free. That is curious to onlookers which is part of the drive in Milford to keep it to two ships a day."
Scrubbing involves spraying emissions with sea water and an agent that combines with the sulphur, which is heavier than the smoke and falls to the bottom of the funnel. Some cruise ships have been targeted for discharging the resulting wash water in sensitive areas.
Smith said while he couldn't speak for other companies, Royal Caribbean had a closed system which meant the water was disposed of in port at a discharge facility, although it was sometimes released into the open ocean.
"There is sulphur in sea water so that itself is not a problem, it's releasing it in port where haven't got a strong tidal or wave action."
This summer a growing number of ships will make more than 1000 port calls around the country, with 370,000 passengers on board — up 13 per cent on last season.
Smith acknowledged the whole cruise sector was under more scrutiny from those worried about the environmental impact of ships and the affect of big ships in particular on small communities or very popular tourist spots.
Already Venice has barred ships from entering its historic centre and there is discussion of ''cruise shame'' along the same lines as the flight shaming movement.
The industry was moving at different speeds to end single use plastics, a hybrid battery powered ship has already been launched by a Norwegian cruise ship and many new ships were LNG powered, which meant lower emissions.
Smith said the main challenge for batteries was storage although he expected that to improve and make it viable in the next 10 to 20 years.
LNG was available at ports in some parts of the world - such as the Caribbean and places in Europe - but not it was not available in this region yet meaning ships had stuck with heavy fuel.
''Even in northern Europe its not in abundance but you'd have to hope that supply will follow demand.''
Show us a plan
The Ovation of the Seas is too big to tie up at any of Auckland's wharves, leading to controversial plans for a mooring dolphin, or extension, to enable such large ships to berth.
That plan, whose costs have blown out, and will be born by ratepayers, has been appealed to the Environment Court by groups opposed to more encroachment into the Waitematā.
The Ovation now anchors in the harbour and passengers and crew are taken ashore by tender.
This year it was revealed the cost of the structure had risen from $9.4 million to $16.9m.
Asked why the cruise industry didn't foot the bill, Smith said: "That's a good question. Our proposition is that we bring significant economic advantage when we visit and we tend to go places where we're wanted and made welcome."
Stats NZ figures released this year showed cruise spending nationwide rose to $570m in the year to June 30, an increase of 28 per cent on the previous year, with Auckland accounting for almost a third of that.
Smith says Auckland could be benefiting more but turnarounds (where cruises start and finish) and re-provisioning were impossible when ships were not tied up. Tauranga was gaining because it could berth mega-ships such as Ovation of the Seas.
Cruise companies faced similar infrastructure debates overseas.
"Dolphins — there are contentious developments all around the world — this debate is not confined to Auckland and I respect the arguments of harbour users," said Smith.
Royal Caribbean has a market capitalisation of $36 billion. It owns port facilities around the United States and would be prepared to look at helping fund them here if there was a viable plan.
"We would certainly look at it. We're currently investing in 75 ports around the world. What it will need in Auckland is a joint venture. As a consortium with developers or government, we would certainly have a very close look at it."
The dolphin would only be available for 15 years and he believed the best place for cruise ships would be further east (although the container wharves are also too short or would need to be rebuilt — and that's if Ports of Auckland was prepared to give up the space) .
''I wonder if the cruise ships will end up at the bottom of the hill coming down from Parnell.''
If there was improved infrastructure Royal would consider bringing in to New Zealand Oasis class ships which are longer and wider than the Quantum class Ovation of the Seas and carry 1500 more passengers - about 6500.
Lyttelton's new cruise terminal is capable of handling Oasis size ships.