Hot temperatures and the public holiday - shown to correlate with increased alcohol consumption - are expected to drive large numbers of party goers and tourists to the water to cool off. A Sydney Morning Herald analysis of a decade of data provided by Surf Life Saving NSW and Royal Life Saving shows rescues at Sydney beaches are greatest on Saturdays and Sundays, and peak on Australia Day and Boxing Day. Of the 249 drownings in 2018, 46 people died on the beaches, 40 in oceans, and 61 in rivers and creeks, with men accounting for 72 per cent of all deaths. About twice as many fatal drownings occur on the weekend, particularly on Sundays and public holidays. Good decision making and alcohol don't mix, Steven Pearce, the chief executive of Surf Life Saving NSW said. "Add to that oceans and rips, and that makes a treacherous cocktail."

Drinking on public holidays is part of Australian culture, Mr Pearce said. Yet many people failed to understand that drinking diminished thought processes and enhanced the risk of something going wrong. About one in five people who drowned on beaches or in the ocean from 2004 to 2018 were drunk or on drugs, he said. Four in 10 of those people had been drinking heavily, with blood alcohol readings four times the 0.05 per cent limit. Only the other day Mr Pearce was involved in a rescue of two young men at Stanwell Park who were "pretty smashed" and had ventured into a rip outside the flags. Their judgement was so impaired they didn't realise they were in trouble and resisted lifesavers' help. Of those who had been drinking and drowned in the ocean or at a beach, nearly nine in 10 were men, mostly aged 20 to 54, Mr Pearce said.

It's a similar story inland, but worse. Around 41 per cent of those who fatally drowned in rivers and streams had been drinking. The majority of drownings at beaches and in rivers occur mid-afternoon. "They've been on the grog at a party or a barbecue, they've been down the beach and (it's) time to cool off after lunch ... That's when water conditions change and it often becomes more dangerous, depending on the beach," Mr Pearce said. Research shows that of those who drowned because of rips, nearly 60 per cent had travelled more than 50km to visit the beach. Another experienced lifesaver (name withheld) described a dangerous mix of tourists coming in from interstate or overseas by public transport as "on the piss, in the water and just off the plane".

Australia Day: People celebrating at Bondi Beach in 2013. Credit:James Alcock Royal Life Saving Society Australia's Amy Peden said it was sad that "inevitably" someone drowned every Australia Day, very often under the influence of alcohol. "The data indicates that there is at least one drowning each Australia Day for the past five years," she said. Three people drowned on January 26, 2018, according to the Royal Life Saving National Fatal Drowning Database. Of the eight fatal drownings that occurred on Australia Day in the past five years, three were known to involve alcohol with an average BAC of 0.164 per cent. There have been more Sydney beach rescues by volunteer lifesavers on Australia Day than any other summer public holiday since 2008. There were a total of 1202 rescues on Australia Day at Sydney beaches, 1151 on New Years Day, and 741 on Boxing Day.

More people drowned at Maroubra Beach over the past decade than anywhere else in NSW with 13 people losing their lives up to December 4, 2018, a Herald analysis of Surf Lifesaving Australia's records found. A dozen people have drowned at North and South Bondi in the same period, and Little Bay beach in Randwick recorded the third highest drowning toll in Sydney with six lives lost since 2008. Water safer experts say no beach can be considered always safe or dangerous because conditions change quickly. They recommend beachgoers stop to check conditions before they enter the water between the flags on patrolled beaches, and check conditions online at Beachsafe. Because it is a tourist destination in one of most densely populated areas in Australia, Bondi Beach is also the busiest place for rescues - volunteers save about 520 flailing swimmers each year.

New research by Ms Peden, the research manager for Royal Life Saving, showed that about 16 per cent of 684 river users - tested at four sites in NSW and QLD across 16 days in 2018, including on Australia Day - tested positive for alcohol. The study was published in the BMC Public Health Journal in late December. Loading Drinkers were more likely to record a higher blood alcohol reading if they were born in Australia, tested in the afternoon (after a day's drinking) and when the weather was hot. On Australia Day nearly four times as many people had blood alcohol levels greater than 0.5 per cent, the study found. This data was collected at Noreuil Park foreshore on the Murray River at Albury which was designated as "alcohol-free for Australia Day". The Murray is the nation's leading river drowning blackspot. It is illegal to drink and drive a motor vehicle or a boat with a blood alcohol reading greater than 0.05 per cent, but it is not illegal to swim under the influence.

When asked about attitudes to drinking, only seven per cent of people said it was okay to drink and drive. In contrast, nearly 21 per cent of respondents thought it was okay to drink alcohol before swimming. Loading Those who drank dangerous amounts of alcohol were also more likely to agree that it was okay to drink and skipper a boat or drink before going for a swim. The only similar research on alcohol use by beachgoers, called Bingeing on the Beach, produced by University of Queensland's Professor Kerrianne Watt, yielded similar results. Testing beachgoers in Queensland aged 18 to 24, Professor Watt found 7.4 per cent recorded a positive BAC. Researchers also found one in four reported drinking within two hours of swimming at the beach in the previous year.