How to spot Perth beaches’ biggest danger this summer – and it’s not sharks

Perth’s weather is heating up and its people are hitting the beach. And if you asked most of them if they worry about dangers below the surface, they’ll surely admit the thought of sharks is never far away.

But if your local is Trigg, City Beach or Scarborough, or if you’re planning to take your children to spots such as Geraldton or the South West this summer, be mindful of a more clear and present danger.

In Australia 26 people drown in rips on average a year, according to coastal scientist Professor Rob Brander.

“That’s more than the average for bushfires, floods, cyclones and sharks combined,” he said.

“WA gets rip currents at Scarborough and Trigg most of the time. And they do not have to be strong to be dangerous. The days people get in trouble are often beautiful days with small waves.”

In 2022/23 WA had 21 coastal drownings, the third-highest number of the states/territories, and 9 per cent of these were rip-related, according to the Surf Lifesaving Australia 2023 National Coastal Safety Report.

In July this year, a City Beach lifeguard had to save two young boys caught in a rip so strong it dragged them 50 metres past the end of the groyne by the time the lifeguard reached the water.

Professor Brander is known as Dr Rip for his groundbreaking scientific work born of a passion for the beach that arose when he was a teenager, grew throughout undergrad and masters degrees, then crystallised in a doctorate in rip currents.

This animation shows the movement of 20 GPS drifters from 10.30am to 2pm at North Cronulla Beach. Professor Rob Brander from UNSW said the waves weren’t that big, about 1.5 metres, but the rips dragged students and drifters 200 metres out to sea. Watch for the exploding firework rip exit. Other rips turn in circles.Credit: UNSW Beach Safety Group

This PhD brought him to Australia, but the waves were what kept him here.

“The first time I caught a bodysurfing wave at Bondi I was hooked, I was never going back,” he said.

“I remember thinking, people actually live here? This is unbelievable. But that applies to most of the Australian coastline.”

Brander is in Perth for the World Conference on Drowning Prevention and premiere of the Rip Current Survival documentary in which he has collaborated.

Professor Brander urges people to stand at a high vantage point, such as car parks, to study the water before entering. Credit: Emma Young

He was the first in the world to measure rip dynamics and characteristics, confirming their speeds at different times of day and their tendency to “pulse”; they can double their normal speed for 30 seconds to a minute as groups of waves come in.

“A simple way to think of a rip is like a river of the sea. When you get waves coming in and breaking all the white water builds up and has to go back out – it gets that water back offshore,” he said.

“Most, but not all, sit in deeper channels between sand bars.

“Whenever you get a surfing beach, you’re going to get rip currents.”

Brander said on most coastlines with smallish tides the most critical time was an hour and a half on either side of low tide. More waves breaking meant more energy driving rips.

“If you are not a strong swimmer even a slow-flowing rip current can be dangerous,” he said.

“People ask me all the time what it feels like. It doesn’t feel like anything. You’re just going with the flow. It’s only when you look around and you see the beach disappearing.”

He said the phrase “white is nice, green is mean” was true for most rips.

Someone evidently felt this warning sign at City Beach needed some additional clarity. Credit: Emma Young

They also frequently occurred against structures such as headlands and jetties and groynes. “Flash rips” were harder to spot, but looked like turbulent clouds.

Brander said most drownings happened on unpatrolled beaches.

“If you want to be safe, swim between the flags,” Brander said.

“If you’re not a good swimmer, don’t go out of waist depth.

“If no one is around, don’t go in the water.”

Strong rips could also sweep people off their feet, however, and water levels could fluctuate.

If this happened, he cautioned against trying to swim out of the rip, unless you were an experienced and strong swimmer.

“If you are a good swimmer, slowly swim to the side. Look for where the waves are breaking and aim for that. The old saying, swim parallel to the beach, is not necessarily right as rips can go at angles,” he said.

He advised people caught in a rip to stay afloat, conserve energy and focus on signalling for help.

“If there are surfers, lifeguards and so on they will be rescuing you. Don’t be afraid to call out to surfers,” he said.

Finally, he said, bystanders should be sure to bring in a flotation device if heading out to help.

“It can be them who end up drowning,” he said.

“For me, all my life the beach has been a place of joy. To have that turned into a tragedy happens far too often.”

The new rip current survival documentary can be viewed by readers of this publication for free, here.

Dr Rip’s Essential Beach Book: Everything you need to know about surf, sand and rips, 2nd ed., was released on October 1.