Australia's most famous beach is braced for an invasion. Up to 50,000 people will converge on the silky white sands of Bondi Beach in Sydney tomorrow to celebrate Christmas Day. The great arc of sand and surf, bounded at both ends by rocky headlands, will be a teeming mass of humanity, with locals and tourists alike sunbathing, swimming and wearing Santa Claus hats with their bikinis and board shorts. Christmas Day at Bondi has become one of the biggest events in the backpacker calendar, with young travellers drawn each year like ants to a discarded ice cream. It is a byword for boozy excess, with groups of sunburned British and Irish backpackers flaunting their national flags and working their way through endless cans of ice-cold beer. But alcohol and the ocean are not a good mix. Last year more than 100 people - many of them well-oiled backpackers - had to be rescued by volunteer lifesavers. Invisible rips and undercurrents make many of Australia's beaches extremely dangerous, and Bondi is no exception. A particularly powerful rip at the southern end of the beach has swept away so many young travellers that it is nicknamed 'the backpacker express'. 'The problem is that after a few beers some people think they are Ian Thorpe, which is all very well until they try to swim back to shore against the rip,' said Bruce Hopkins, a senior lifeguard at Bondi. So, this year, the council which manages Bondi has banned all alcohol from the beach, much to the dismay of backpackers. Around 100 police and security guards will guard the ramps leading down to the beach, confiscating illicit booze. But many tourists are expected to flout the ban, smuggling alcohol on to the beach. 'People will sneak booze in somehow or other,' said Robert Ryan, the manager of the Bondi Beach YHA. 'The ban is ridiculous. The council has gone completely over the top.' As if the booze ban was not enough to dampen the Christmas spirit, the council has also announced that smoking on the beach is now prohibited - each year millions of cigarette butts are left behind. Those desperate for a cigarette will have to leave the sand and light up elsewhere. Exactly how the authorities intend to police the ban amid such a large crowd remains to be seen. 'We don't want to be party-poopers,' a council spokeswoman said, pointing out that backpackers will be able to drink if they are prepared to pay A$50 ($297) for an all-day dance party just behind the beach. 'We just want to ensure people have fun safely.' Christmas at Bondi may never be the same again.