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You'd expect sailing to be an emissions-free sport, but what about the chase boats?
This year, each of the America's Cup support vessels were powered by several big petrol-guzzling outboards, generating about 1000 horsepower per boat just to keep up with the space-age foiling yachts.
But next time around, Team New Zealand wants them to be powered by green hydrogen.
It's working with a Christchurch company AFCryo to develop the emissions-free technology.
Max Towle asked Team New Zealand's chief executive Grant Dalton about the push for change: