Once, the Prime Minister's visit to Antarctica this week would have placed him among a select group. Not any more. He will be just one of about 50,000 people to visit the frozen continent this year. The number has increased rapidly over the past decade thanks to Antarctica becoming a top destination for those keen to see some of the world's most endangered places.
New Zealand is playing a small role in this boom, sending 300 tourists a year to visit the Ross Dependency, contributing about $5 million to the national economy in the process. John Key, as Tourism Minister, will be aware that at least one New Zealand operator has suggested further advantage should be taken of the continent's unique attractions.
It can be argued that tourism has had a relatively benign impact so far. Having seen Antarctica in a pristine state, people return home with a heightened concern about environmental challenges confronting it. This outweighs the effects on sites they have visited.
Their impact has also been managed by strict rules imposed by states of the Antarctic Treaty system which dictate, among other things, that ships with more than 500 passengers cannot land them, that only 100 passengers may be landed at a time, and that tourists must stay 5m to 10m away from wildlife.
This process has also been underpinned by a tourist industry largely respectful of Antarctica's role, first and foremost, as a natural reserve devoted to peace and science. The industry is keen to promote its credentials as a purveyor of so-called "eco-tourism".
But that is only a word. It seems inevitable that the demand to visit Antarctica will attract some companies happy to use the tag but less keen on honouring it in practice. Already, some of the tourist ships that operate in Antarctic waters are registered in countries that are not members of the treaty and, therefore, not subject to any decisions made. They can get away with less stringent safety regulations.
Heritage Expeditions, which operates in the Ross Dependency, suggests that tourism there could easily be far more valuable to this country. It suggests this as an alternative to the controversial toothfish industry in the Ross Sea, which earns about $20 million for New Zealand companies.
"You could easily realise $20 million from tourism while having a lot less impact on the environment," says Aaron Ross, of Heritage. That seems doubtful. Either way, it should not be a matter of choosing one or the other. The operations of both should recognise the environmental importance of Antarctica.
Large numbers of tourists will increase pressures on sensitive Antarctic ecosystems and wildlife. Penguin breeding sites, for example, are already targets for big groups of tourists. Sea-ice retreat is merely increasing the danger.
So, too, are the increasing numbers of big cruise liners, the vast majority of which reach the Antarctic Peninsula after a two-day trip from South America. An accident to one of them could occur in waters that are too isolated and in weather that is too extreme for either rescue or environmental clean-up.
Now is an appropriate time to analyse the lessons of the first stage of tourism in Antarctica. Other questions need to be answered. There are occasional mutterings about building hotels there. Some operators would like tourists to be given greater freedom of movement.
Others, more wisely, point to the need for more stringent checks of compliance with the tourism regulations. Always, the guiding principle should be a safe and environmentally responsible approach to tourism. Irreparable damage is not an option for the world's last great wilderness.