What Is A Rip Current?
Rips can be identified by deeper, dark coloured water, fewer breaking waves and a rippled surface surrounded by smooth water. The most common type is a chanelised rip. These rips occupy deep channels between sand bars and they can stay in the same place for days, weeks and even months.Then there’s boundary rips - which can also be channelised and are found against headlands and other structures reaching out into the ocean like piers and jetties. Sometimes these can be almost permanent. But one of the most dangerous and unpredictable rips is the Flash Rip.
To be able to form, rip currents need breaking waves. It’s the spatial variation in the breaking waves, normally caused by undulations in the sand bars that commonly begins the process of a rip current forming. A flow develops, that moves from the region of intense wave breaking toward the region of reduced or no wave breaking, inside the surf zone This flow is the pathway of least resistance for outgoing water – often a perfect channel – just like a river of the sea.
Typically rip currents are about 10 to 50 metres wide and they can flow anywhere from 50 to 100 metres offshore normally. But Dr Rob Brander has measured rip currents that have flowed 400 metres offshore
To study how rip currents Doctor Rob brander places mobile devices called drifters directly into the currents. These drifters have onboard GPS units that record rip current data such as flow speeds and flow direction both inside and outside the surf zone.
The average rip current flows offshore at speeds of about half a metre to one metre per second. But they all have a tendency to pulse and what that means is that suddenly the rip current can just dramatically double in speed in a matter of thirty seconds and then you’re talking speeds of two meters per second which is literally Olympic swimming speeds.
How To Survive A Rip Current
Not all rip currents flow straight out to the breaking waves. Some rip currents flow in a circular movement within the surf zone. These are referred to as rotating eddies. Rip currents are very dynamic – they can change direction quickly.
Rob Brander’s research has revealed that there is no single escape strategy that is guaranteed to get you out of a rip current. Instead you have options based on the conditions and the behaviour of the rip.
The golden rule is to never attempt to swim against the current – they’re just too powerful. Remember to stay calm and focus on floating. Just go with the current and raise your hand for help. Depending on the flow of the rip, floating will normally deliver two scenarios:
A circulating rip current should float you back around to either a sand bank or put you close to breaking waves which will help you get back to shore.
A current that flows directly offshore will normally float you just beyond the breaking waves where the rip will cease to operate. At this point you can either continue to float and wait for rescue or you can swim around the rip and back to shore.
The other option you have – and this applies only to good swimmers – is you can try swimming parallel to the beach in either direction as you float with the current. In some situations this may free you from the rip.
It’s really panic that is the biggest killer when it comes to rips. Rips don’t drown you that don’t pull you under. Panicking will drown you. People panic because they find themselves being taken quickly off shore, the situation is outside of their control, it’s a scary experience.
And what you need to do when you’re caught in a rip is try and take control of the situation yourself. You can float and you can assess what’s going on – do you want to swim this way, do you think that will work. If it’s not working, float a bit and swim the other way or just float. If you’re constantly thinking about the situation and the options you have you’re in control of the situation, provided you haven’t exhausted yourself, but you do not want to panic. Anything that will eliminate panic is the best approach.
- Each year (on average) rip currents claim more lives in Australia than bushfires, floods, cyclones and sharks combined.
- Rip currents are responsible for an estimated 90% of the over 10,000 beach rescues made in Australia each year.
- Australia has over 11,000 beaches and scientists estimate that up to 17,000 rips could be operating across Australia’s beaches at any given time
- Almost all of Australia’s rip currents fatalities occur on unpatrolled beaches or outside of the red and yellow flags
- Less than 4% of Australia’s 11,000 beaches are patrolled by Lifesavers or Lifeguards. This means that there are a lot of beaches and a lot of rips where any beachgoer could find themselves in serious trouble.
- Many coastal tourist parks in NSW are situated closest to unpatrolled beaches that are rated as hazardous in terms of rips.
- Many of Australia’s rip current drownings take place on isolated stretches of coastline where the nearest patrolled beach is neither close nor convenient.
- The simplest way to describe rip currents is that they’re like river of the sea: strong, narrow, seaward flowing currents that extend from the shoreline out beyond the breaking waves. They exist to bring all that extra water that’s coming in with the breaking waves back offshore.
- The majority of rip current drowning’s take place underneath bright blue skies, moderate waves and what appear to be perfect beach conditions.
- Young males between the ages of 15 and 39 are the most likely to die in rip currents.
- Rips are not undertow, they won’t pull you under because there’s no such thing as an undertow. They’re not rip tides because they’re not a tide, they’re a current and they flow pretty steady and they won’t take you to New Zealand.
Watch Rip Current Heroes Wednesday December 20 at 9.pm AEDT/NZDT on National Geographic.