Most of the time Lake Eyre, in the Australian interior, is a vast expanse of mud topped with a thick layer of salt. Very occasionally, after flooding rains, it fills with water attracting a rich variety of birdlife.

This year is one of those rare times, but bird-watchers are not the only humans flocking to the lake. A group of yachtsmen has been sailing on its shallow waters, incurring the wrath of local Aboriginal people, for whom it is a special place.

Formed in 2000, the Lake Eyre Yacht Club is one of Australia's more eccentric organisations. In a country with 60,000km of coastline, its members are dedicated to sailing in the desert. In rainy years, they keep a close eye on the great saltpan in the continent's centre.

But the lake is central to the culture and mythology of the Arabunna people, who regard sailing there as sacrilege and fear its impact on Lake Eyre's delicate ecosystems. "For us, it's a sacred place. It's like Uluru [Ayers Rock]," says Aaron Stuart, chairman of the Arabunna's native title claim.

With the two sides at odds, the South Australian national parks body won't issue sailing permits unless the Arabunna consent.

That has not deterred the club's commodore, Bob Backway, who has already been out on the lake twice this year.

Backway dismisses the Arabunna's objections, claiming they are based on a "bogeyman story" dating from an era when it was hazardous to venture out on to the lake. "We have modern technology now," he said.

"I'm not saying I don't respect Aboriginal heritage, but there are no carvings or burial sites there. The Arabunna are trying to throw their weight around."

Stuart denies that, saying that the lake, with all its tributaries, is "where trade happened, and ceremony, and song and dance". Moreover, he says, his people's ancestral spirit, Warrina, lives in the lake and is disturbed by boats. "We want people from Australia and around the world to come to our country, but let's leave it alone and just enjoy its wild natural beauty."

The Arabunna have lodged a native title claim which, according to their lawyer Stephen Kenny, is expected to be approved by the state government this year.

Backway said Australians had a common law right of access to waterways, and he claimed events at Lake Eyre could set a precedent. He's planning to sail there again, possibly next month.