It was a cold, windy and intermittently rainy morning, but a chance to be a muse for an internationally renowned artist doesn't come around often.

Before sunrise on Saturday, thousands of people descended on Sydney's iconic Bondi Beach and stripped off to pose for American photographer Spencer Tunick, who is known for his large-scale nude shoots.

"This was one of my most difficult works ever," he said.

"Bondi is difficult. It's such a harsh place but a beautiful place at the same time.

"The sea is so loud, it's like a hundred freight trains behind me."

Tunick partnered with Skin Check Champions for the project, a charity raising awareness about the prevalence of skin cancer in Australia and the importance of getting regular check-ups.

The 2,500 naked bodies photographed for the work represent the number of Australians who die from skin cancer each year.

As well as posing, each of them fundraised for the organisation, which is hoping to use the money to launch a nationwide skin check pilot project.

"I had melanoma removed myself, from my arm, and I really would love to spread the word that everybody should get their skin checked," one participant said.  

"Everybody knows somebody who's been affected by skin cancer in Australia."

While the thought of being naked with a group of strangers had daunted some, they said they soon got used to it.

"They did a countdown and then everyone just did it at the same time… it was surreal. It's never going to happen again in Bondi. Definitely a once-in-a-lifetime opportunity," said one.

"The nudity is the least of it. It's the sand in the face and the salt in the air," laughed another.

After a shoot that took well over an hour, many were keen to get home to a warm shower.

Bondi Beach is the second Sydney landmark to be chosen by Tunick as a backdrop for his work.

In 2010, he photographed 5,000 naked people on the steps of the Opera House as a tribute to the city's Gay and Lesbian Mardi Gras.