Recent shark attacks in Australia has triggered some quite bizarre responses from authorities that include fitting sharks with transponders that automatically trigger warnings to beach goers via twitter, to baited-hook lines, and shark nets along beaches.
Stealth wet suits have been designed. At the same time tracking devices fitted to sharks that frequent estuaries and bays has shown that sharks regularly cruise through popular swimming ares without any attacks occurring.
This has triggered diverse response from 'Kill those sharks' to 'I told you sharks are no threat really'. It is a matter of ignorance is bliss.
However, there is a far deadlier menace lurking along the beaches that needs to be better understood.
It is rip currents on beaches. Australian Statistics showed that in 2012:
So why are rip currents, which cause most of the deaths on beaches in Australia, so deadly?
Rip currents are strong, narrow channels of water that returns the water carried to the beach by waves back to deeper water. Most people who go surfing experience the tug of rips regularly, but they know what they are and how to avoid them.
Under certain circumstances the rips may form suddenly when a sand bank collapses or the wave pattern changes. In some locations regular rips may occur near rock at the end of the beach. Board riders use these locations as 'elevators' to pull them out past the line of the breakers.
Despite the strength of rips, they generally dissipate naturally just beyond the area where the waves are breaking. This may be only 25-50 meters out from the sand bank or area where the waves are breaking.
If you understand rip currents, and swim with them, and then return to the beach, there is little real danger if you are a good swimmer.
Problems occur with poor swimmers, especially those that panic, and try to swim against the current.
Rips are one of the major reasons why people drown at the beach.
Why rips form is quite simple. The breaking waves and the white water brings a large volume of water close to the shore inside of the wave breaking zone. The water accumulates and has to go somewhere to restore the balance. Usually the water simply exists all along the beach, sometimes creating a back wave. Occasionally the water rushes out in a narrow channel forming a rip.
Most experienced swimmers can recognise a rip by obvious signs that the water is rushing out at that point. Quite often it is 'white water' or the channel is deeper. Also, because of the deeper depth, the waves are smaller and there is often a break in the line of waves that break on the beach, coinciding with the rip location.
Inexperienced visitors to the beach don't know how to recognise these signs and how to avoid these areas. The smaller waves often deceive inexperienced swimmers who may wrongly choose these areas as a better place to swim. Poor swimmers may quickly get into trouble if they are swept off their feet into deeper water. The tug of the rip heading out to sea causes panic and unfortunately many people drown after being caught in rips.
Major incidents occur when a sandbank collapses and a strong rip develops suddenly in an area crowded with swimmers. In some cases 10, 20 or 100 swimmers may simultaneously get into trouble, even in areas patrolled by 'life savers'. This can quickly overwhelm the rescue attempts. Help may take time coming and people can drown very quickly under these circumstances.
Rips are quite common and virtually even beach will have one or more rips of various sizes at any one time. Some beaches are renowned for rips.
Despite the popularity of beach swimming in Australia it is estimated that half of regular beach goers are unaware of rips, how to spot them and what to do if they get caught in rips. International visitors and occasional beach goers are high risks, especially those with poor swimming ability. Even competent swimmers in still water can be challenged by the rough water at the beach. Panic can bring good swimmers undone.
Surveys conducted by a research team at the University of New South Wales in Sydney found that about 21 people drown in rip currents each year. This death rate is higher that the average annual deaths from bushfires, floods, cyclones and shark attacks. There are a very large number of near-misses and people being rescued in patrolled areas. Rips are by far the most common cause of calls for assistance from life savers on Australian Beaches.
Despite the high death rate much less is being done to reduce the risk of rips than is being done to reduce the risk of shark attacks. In some cases, people drive to the beach but don't go in the water because they are afraid of sharks. They are unaware that the probability of being injured or killed on the way to and from the beach is probably 1,000,000 times greater than a shark attack.
Researchers and authorities have called for improved education about rips and signage along major beaches to reduce the risk. The major issue is to teach people not to panic, be aware of what is happening and to simply float out with the rip and either return to the beach at another location, or to call for assistance. Panic is the cause of deaths from rip currents.