Swimmers have won their High Court battle with "the nanny state" over "the right to take risks" and bathe in a natural pond on chilly winter mornings.
The legal challenge was brought by the Hampstead Heath Winter Swimming Club against the Corporation of London.
Last July the Corporation rejected the club's proposals for early morning, self-regulated swimming in the Mixed Pond on the heath in north London.
The club wants the pond reserved for the exclusive use of experienced club members during the winter season and not open to the public.
The Corporation's refusal was linked to safety fears and concern that it could be at risk of prosecution by the Health and Safety Executive.
But yesterday Mr Justice Burnton ruled the Corporation had fallen into legal error and said swimmers should be able to swim at their own risk.
He spoke out in favour of "individual freedom" and against "a grey and dull safety regime" being imposed on everyone.
He said: "The Corporation's grant to the club of permission to swim unsupervised in the mixed pond will not of itself render it liable to prosecution" The judge ruled the Corporation's refusal to allow club swimmers to bathe when lifeguards were not present at the pond was based on a misapprehension of the law.
Later several swimmers welcomed the ruling as "a victory over the nanny state" which could also help others take risks for fun.
Mary Kane, chair of the winter swimming club, said: "This is great news for the club and for public bodies like the Corporation.
"The judge has clarified the scope of the Health and Safety at Work Act, and the Corporation, freed from the threat of prosecution, can now grant the club the permission the club has been seeking for the past two years.
"This was a test case with wide implications for all open water swimming in England and represents another successful attack by ordinary citizens on the 'nanny state'."
The bathers of Hampstead Heath, who come from all over the capital, launched their challenge after the Corporation cut back on the hours lifeguards were provided - while refusing to let people swim unsupervised.
There are three ponds - the men's, ladies' and mixed - and the move meant members of Hampstead Heath Winter Swimming Club were prevented from going for swims before work .
At present the three ponds are open only while lifeguards are on duty.
The High Court heard the Corporation had traditionally provided lifeguards from dawn until dusk, but changes in the opening hours in March 2003 meant early morning swimmers were no longer able to swim before going to work.