Eco-tourism in the Antarctic has spiked in the past decade, and some operators predict locally run tours could eclipse the profits of New Zealand's controversial fishing in the Ross Sea.
Up to 50,000 people now visit the ice each year on the back of a "responsible" tourism boom and a renewed interest in heroic explorers such as Ernest Shackleton.
Most operators set off from South America and tour the Antarctic peninsula, but a fraction of the visitors travel to the Ross Dependency, some of them via a single New Zealand operator, Heritage Expeditions.
Heritage founder and biologist Rodney Russ said the trip to the Ross Sea, which included landings on sub-Antarctic islands and penguin, whale and birdlife sightings, had no parallel in the tourism market.
"You don't take the trip, the trip takes you. It gets into your body, your skin, and you can't get rid of it."
His company will take two groups of 50 people this summer on a month-long trip based on retracing Shackleton and Robert Scott's 19th century expeditions. The tours were sold out 12 to 18 months in advance.
Heritage-run voyages are targeted at wealthy travellers who are more interested in science than lying on a deckchair.
Heritage tours range from $600 to $1200 a day, with a typical 28-day trip requiring a hefty $20,000.
The small cluster of ice-strengthened ships that venture into the Ross Sea (which New Zealand has claimed since 1923) generate at least $5 million a year for the New Zealand economy.
Operators feel there is room for expansion of tours to the region.
Mr Russ's son Aaron, who also works for Heritage, said: "It's always going to be a niche industry but it's a very lucrative one that's currently not realising its full potential."
Some environmentalists believe tourism is the cleaner alternative to fishing in the Ross Sea.
New Zealand earns about $20 million from its toothfish industry in these waters, but there is an environmental push for a marine reserve in the region.
Filmmaker and marine reserve advocate Peter Young said responsible tourism was "the answer for the Ross Sea".
"Tourists take photos, become ambassadors, and share the reasons the Ross Sea is special," he said. "The marginal fishery is full of conflict and danger."
Aaron Russ said tourism could compete with the profits of the toothfish industry: "You could easily realise $20 million from tourism while having a lot less impact on the environment."
But he stressed that any expansion would have to be tightly regulated.
A United Nations report in 2007 warned of greater risks to Antarctica's environment as sea-ice retreat produced new opportunities for tourism. Since that report, there have been a handful of incidents around the Antarctic peninsula.
Cruise ships have grounded or become trapped in ice, and a Canadian vessel, the MS Explorer, sank off the Antarctic in 2008 after striking submerged ice.
Organising trips to the Ross Sea is a logistical nightmare. Ships have to sail through pack ice for 36 hours, and contend with gut-wrenching swells and changeable weather.
Aaron Russ said his company had to prove it would have an invisible footprint, and had annual evaluations to prove it would cause only "a minor or transitory impact".
Heritage Expeditions is not allowed to discharge from its ship once it is south of 60 degrees, constantly checks its hull to ensure it is not carrying potentially harmful organisms, and carries out biosecurity checks on passengers before all landings - not a seed or crumb of food goes ashore.
Despite these challenges, Aaron Russ said, a New Zealand-led tourism market in the Ross Sea was not out of the question. "The limited side is certainly supply, not demand."
* Began in 1950s-60s with scenic overflights and private yacht voyages.
* Visitors grew to 6800 in 1990, and 37,000 by 2010.
* 300 tourists a year visit the Ross Dependency as a destination.
* Ross Sea tourism worth at least $5 million to NZ economy.
* Tourist operators must prove they have only a minor impact on the environment.
* Ships with more than 500 passengers cannot land passengers.
* Only 100 passengers may be landed at a time.
* Tourists must stay 5m to 10m away from wildlife.
Tomorrow: The future of the Ross Sea.