Escaping Canberra's summer heat could have put thousands on the wrong side of the law, according to a 1950s law that requires swimmers to dress in keeping with "the observance of decency".
The ACT Government will this week move to update existing rules governing territory-owned swimming pools, removing outdated restrictions on fashion and behaviour and strengthening responsibilities for venue managers.
The law in place had its origins as the Australian Capital Territory Ordinance relating to Public Baths and Public Bathing.
Signed by Governor-General William Joseph Slim in December 1956, it bans "filth and other offensive matter" from public pools and requires swimmers to dress in keeping with community expectations.
"A person shall not appear in any public baths unless he or she is clad so as to secure the observance of decency," the law says.
"Where a person in any public baths is not clad so as to secure the observance of decency, the manager of, or an attendant at the baths or an inspector may direct the person to clothe himself so as to secure the observance of decency."
It also bans admission of anyone "in a state of intoxication", acting in a "riotous or offensive manner" and requires earthenware not to be broken. It gives the relevant minister powers to sell or hire bathing costumes, towels and other articles.
Some of the laws more serious clauses attract a penalty of 50 pounds, about $2400 in today's money.
The supreme authority of regulating bikinis and board shorts today falls to Sports Minister Shane Rattenbury, who will introduce a bill to modernise the laws on Thursday.
"I think it's fair to say that community expectations of decency might have changed somewhat since 1956 and the legislation needs to change in line with these expectations," Mr Rattenbury said.
"This legislation supports the great Australian recreation of swimming and aims to support a positive atmosphere and safe environment when visiting territory-owned public pools."
If passed, the laws would improve administration practices for pool managers, and update government processess around business needs. Mr Rattenbury said rules against swimming aids, balls and toys would be changed, with managers able to ask for the items to be removed if they pose a risk to safety.
"Pool operators will for the first time be supported in addressing [anti-social] behaviour through an easy and transparent early intervention approach that will assist in modifying the behaviour through an initial warning, before progressing to having the person removed," Mr Rattenbury said.
Leanne Dempsey of Canberra online store The Darling Sisters said some swimmers were becoming "braver by the 1950s".
Men would have worn trunks, slightly longer than today's board shorts and women wore costumes with lower cuts on the bottom and higher at the top.
"Bikinis were certainly around. Bottoms went up to the waist, with the patch of skin below the navel and the hips covered up," she said.
"A lot of people at the public bathing pools at the time wouldn't have got too excited about showing off too much skin."
Ms Dempsey said new fabrics and styles meant the original ordinance covered an in-between period in Canberra, before much more revealing costumes became commonplace in the 1960s.
Further reforms for the industry will be considered for territory-owned public pools in 2015, but Mr Rattenbury said changes would only come after consultation with stakeholders.