While Kathy and her husband, Stephen, have always been "closet nudists" – comfortable being naked in their home – they are newcomers to the nudist club scene.

As we sit around a plastic table in dense bushland on the fringes of Sydney, the retirees explain how they came to be regulars at Australia's oldest nudist club.

"We saw an advertisement, found out it was only a few kilometres away from home, came down and went 'gee, nobody has got horns on their heads here'," Stephen says. "I didn't take my clothes off the first day but when I did I didn't worry about it at all because you feel out of place wearing clothes and everyone just accepts you as you are," Kathy adds.

The pair are members of the Heritage Australia Club, which was formed in 1949 and is housed on an isolated 10-hectare property overlooking the Georges River in Minto Heights.

"There are no expectations. Nobody expects anything from you. You can just be yourself. As soon as you close that gate behind you, you just seem to relax and all the pressure is gone," Kathy says.

The club has about 50 paid members who attend monthly functions at the property, which largely consists of a few basic cabins and a covered outdoor area. The meeting that I attend feels something like a family picnic in the park – except no one is wearing pants.

The club's members drink white wine out of plastic cups, chatter about boats they used to own and books they have read and go for walks on rough hewn bush tracks.

While I am repeatedly assured that nobody would look at me twice, I have decided to remain a "textile" (the name given to non-nudists). 

Photo: Wolter Peeters

Like a traditional country club, there are rules of entry and etiquette at nudist clubs.

If you are want to use one of the shared chairs, you must sit on a towel.

When you talk to people, you should look them in the eye.

Friends and family are welcome to attend, but it is always polite to ask other members first.

There is, of course, a "club uniform", but there is no pressure on members who want to stay dressed.

Generally, members follow a simple mantra: if you would not do it with your clothes on, you probably should not do it naked.

But there are some particular hazards that one should be alert to before stripping off including sunburn, bites and "grass cuts" on delicate places.

One of the club's oldest nudists Jill, 75, says there is genuine friendship between the members as everyone is equal when they are naked.

"If you've got nothing on, you've got nothing to hide. What you see is what you get and it doesn't matter where you come from, how old you are, how rich you are, it's the person that you get to know," Jill says.

"It's the feeling of freedom. It's just a totally different feeling to being dressed."

But the future of club nudism is not looking bright, with membership falling dramatically over the past three decades.

The Australian Naturist Federation's president Greg Serow says the federation has 4000 members, about 70 per cent fewer than in the 1970s and '80s.

Mr Serow describes those decades as the "golden days", where club membership surged on the back of the popularity of nudist beaches. "The world sort of seemed to be in this amazing place where anything was possible and everything felt free," Mr Serow says. "Naturism or nudism was incredibly popular. It was just the thing that everybody did all the time."

Photo: Wolter Peeters

Club membership is now at the lowest it has ever been, Mr Serow said, with several factors to blame.

Nudist resorts have drawn members away from clubs by providing a more leisure-based, commodified opportunity to go naked without any obligations such as annual fees or duties.

Mass media has led to body image policing and self-consciousness, creating much greater shame about the naked body.

Some nudists even point to the rise of the "Slip, Slop, Slap" campaign and skin cancer awareness, which has made people think twice before exposing their body to the sun.

In addition to this, public social nudity has always struggled for legitimacy.

University of Sydney Associate Professor Ruth Barcan, the author of Nudity: A Cultural Anatomy, said a negative stigma still surrounds social nudism with adherents construed as comic at the least and dangerous at the worst.

"[Nudism] is a rupture of one of the most fundamental social rules of any modern society and it is not the norm socially in any modern society, so in that sense it's going to have to have stigma attached to it," Associate Professor Barcan said.

"Therefore equally part of nudism has always been a very strong public line about it being non-sexual, about it it being wholesome, about being close to nature."

Indeed, many nudists I speak to are quick to emphasise that there is nothing sexual about their nakedness.

At the Heritage Australia Club, I am told within minutes of arriving: "Men don't get erections here, they just don't".

Many regular nudists are private about being part of a club, fearing their nudism will harm their careers or upset family members and friends.

"I think there are a lot of negatives from television and people don't realise there is a huge difference between swingers, hedonists and naturists," club member Stephen says. "I think it is just ignorance."

But as membership declines clubs are finding it difficult to attract a younger generation that could ensure their survival.

At the Heritage Australia Club members range in age from late 20s to mid 70s, although the majority fall into the older age bracket.

Stuart Whelan, the editor of The Australian Naturist Magazine, said young people were still interested in nudism but were not attracted to the organised club structure. 

Photo: Wolter Peeters

"There seems to be interest in the clothes-free lifestyle but it is a lot less organised, it is more spontaneous. Things like [festivals] Confest or Burning Seed, where nakedness is just part of the scene," Mr Whelan said.

Mr Serow, from the naturist federation, said Generation Y was more interested in gratification than commitment to a club.

"They don't want to be a member of anything and clubs have committees and working bees and duty days and a lot of people these days don't want to get involved in associations like that," Mr Serow said.

"Young people are not talking about calling themselves nudists, they are just getting their kit off."

While there are no clubs specifically for young people, Mr Whelan said some had tried to make themselves a more attractive option.

Older clubs, he said, had attempted to modernise by adding swimming pools, redoing club houses and experimenting with new social events.

"Clubs are a particular breed unto themselves and some are struggling for members but others have made some very clever changes and are meeting the members' needs and thriving," Mr Whelan said.

"I think that unless clubs change and meet the needs of the young population they will go."

There are 50 registered nudist clubs across Australia, with the bulk in NSW, although some put the figure as high as 500 when it includes those that are unregistered.

Heritage Australia Club president Michael is upbeat about the future of his club, despite it having 80 per cent fewer members than it did in the 1980s.

Michael said he was confident the club would survive and the key would be encouraging people who are "home nudists" to make the jump to public nudism.

"There are a lot of people out in society who are closet nudists and just need a bit of a prod to come to the club, they might read about nudism in the newspaper for example, and decide to be game and give it a try."