The festive period has been marred by the deaths of four people in NSW waterways over the Christmas long weekend.
After a 36-year-old man drowned in the Hawkesbury River on Christmas Day, two teenage girls were killed in a boating accident near Tamworth on Tuesday.
The girls, aged 13 and 14, were being towed by a boat on the Namoi River, northwest of Tamworth, when they hit a tree stump about 5pm.
Also on Tuesday, a man in his 60s could not be revived after being pulled from the water while scuba diving at Black Neds Bay in Lake Macquarie, police confirmed.
Emergency services were called to the Swansea area about 2.20pm and despite the efforts of witnesses and paramedics the man could not be saved.
Police in Wagga Wagga are also continuing the search for a swimmer who reportedly did not resurface while in the Murrumbidgee River on Tuesday.
The report was made to police about 8.30pm, leading to a search involving volunteers, SES, NSW Ambulance and police.
The search resumed on Wednesday, despite no person being reported missing to police.
Paramedics have responded to 40 water-related incidents in the past four days, 12 of which involved children.
NSW Ambulance Inspector Kay Armstrong urged people to be especially vigilant around waterways during the Christmas and New Year period.
"That includes looking after children in pools, being between the flags when we're on the beaches and in patrolled areas, and making sure we don't mix alcohol and drugs with water-related activities," she said.
It comes after Surf Life Saving NSW reportedly conducted 630 rescues across state in the past three days.
Premier Dominic Perrottet said the holidays continue to be a high-risk time for swimmers, surfers and boaters across the state.
"Whilst it's been great to see people across NSW flocking to the beach, the river or the pool ... I urge everyone to continue to remain vigilant and stay safe in the water," the premier said at Sydney's Coogee beach on Wednesday.
Given 4000 rescues are performed annually, the recent spike of more than eight per hour was worrying.
"There are simple steps families can take to stay safe," Mr Perrottet said.
"Please supervise children, swim between the flags, wear a life jacket when required and always listen to the warnings from emergency service personnel."
Emergency Services Minister Steph Cooke said Surf Life Saving NSW's 75,000-strong volunteers base was out in force at nearly 130 locations along the state's coastline.
Fifty-five people died across NSW waterways in 2021, the deadliest year on record.
Since Christmas, another five people have lost their lives in water-related incidents in Victoria and South Australia.
