Frequently Asked Questions
- How does the Shark Shield effectively deter sharks?
All predatory sharks have highly sensitive electrical receptors called the “Ampullae of Lorenzini” located in their snouts. These tiny gel filled sacs can only sense electrical current from prey at very close distances, typically less than one meter. As sharks can only sense electrical currents at very short distances and electrical currents are dispersed rapidly in water, the myth that sharks can sense electrical current at great distances is not true; as a result electrical shark deterrents do not attract sharks
The powerful, but localised electrical field generated by Shark Shield devices cause the sharks gel filled sacs to spasm and the shark to flee the immediate area. There are no known long-term adverse effects to the shark and as a result Shark Shield devices support the conservation of sharks by removing the need for culling or other lethal means of managing human and shark interactions. Shark Shield devices do not affect other ocean creatures.
- Does the Shark Shield attract sharks?
No! As sharks can only sense electrical currents at very short distances and electrical currents are dispersed rapidly in water, the myth that sharks can sense electrical current at great distances is not true; as a result electrical shark deterrents do not attract sharks.
Sharks are not attracted to electronic shark deterrents because sharks would only be attracted (if at all) to a deterrent at the point at which the electric field strength (of the deterrent) has dropped off enough to represent a prey-like stimulus (approx. 1-100nV/cm), at which point, if they approach the device they should quickly realise that this is not prey (as the field strength will increase greatly) and then subsequently be deterred. Therefore, the question is at what distance from the device does a shark experience a field strength of approximately 1-100nV/cm and from research by the South African National Space Agency the modelling shows the field strength up to about 6m from the device would drop of very quickly to less than 1-100nV/cm
Sharks have an aray of senses, and each one is used at different distances from their prey. The senses used for electrical perception are only used at close range.
Sound - a long range sense (several kilometres)
Low frequency vibrations travel hundreds of meters through the water and are known to attract sharks. Typical sounds might be struggling fish or humans swimming.
Smell - a long range sense (several hundred metres)
Sharks will follow a scent trail over considerable distances. Blood, body fluids and secretions from shell fish may deposit a trail several kilometers from the source.
Pressure - a medium range sense (less then 100 metres)
The sharks lateral line and pit organ allow them to sense changes in pressure.
Sight - a medium range sense (less than 100 metres)
Most of the sharks that pose a threat to us have excellent eyesight and can readily track prey by sight, even in low light.
Electrical perception - a close range sense (less than 1 metre)
A particularly unique sense used by sharks at close quarters, consists of hundreds of tiny gel filled pores around the snout. These are known as Ampullae of Lorenzini and are used to pick up the electrical signals emitted by the nerve impulses from living creatures. When a shark closes in for an attack, a protective membrane pulls back over its eyes rendering it temporarily blind. For the few seconds this may take, the shark is able to track its prey by utilising its Ampullae of Lorenzini.
- If I am wearing a unit, but my buddy/mate is not, is he/she more prone to attack?
Anyone not wearing a Shark Shield is at more risk of being attacked than somebody who is wearing a unit.
However the fact that one person is wearing a unit does not mean that those around him/her are placed at greater risk than if nobody in the group was wearing a unit.
THE UNIT DOES NOT ATTRACT SHARKS.
- What sort of testing has been done on the Shark Shield units?
The electronic wave-form used in the Shark Shield has been on the market since 1995, in the guise of the Shark POD, and has proved its effectiveness in the field time and time again. Click here to view our testimonies.
The Natal Sharks Board test program, was carried out by a group of scientists, including physicists, marine biologists, electronic engineers and a large number of professional divers.
The Shark Shield has been thoroughly tested in the laboratory, and on site with Great Whites, both in Cape Town, South Africa and Neptune Island, South Australia. Field testing of the Shark Shield on predator sharks involves attracting sharks using blood and offal. The unit is turned on and placed into the water with fish bait attached to attract the shark. The shark''s behaviour, as it investigates the food source, is then observed and recorded. The testing conducted to date proves conclusively (100% of the time) that sharks detest the effect the field has on them and will keep a safe distance away from the wearer.
Field testing involves attracting sharks using blood and offal, under stringently controlled conditions. The unit is turned on and placed into the water with fish bait attached, to attract the shark. The shark''s behaviour is then observed and recorded as it investigates the food source. The testing conducted to date proves conclusively (100% of the time) that sharks detest the effect the field has on them, and will keep a safe distance between themselves and the Shark Shield. These tests were completed by independent marine biologists. Click here to view footage of field testing.
Remember: This testing is conducted under the worst possible scenario. The shark is stimulated, hungry and excited. This is a situation that any responsible person will avoid at all costs.
In addition to the proof discussed above, Shark Shield has recently gained credibility by being issued with a NATO stock number. This involved a testing regime by the Australian military. It is currently used by the Australian Elite Military, the Army, Navy, Police and Professional Divers and the US Coast Guard.
- Can we guarantee the Shark Shield works?
Certainly it works.
Apart from the unsolicited testimonies from users, stating how their lives have been saved by this technology, we have years of conclusive scientific testing. It is important to note that all our testing is conducted in extreme circumstances in a bloodied and baited environment.
However, it must be remembered that all sharks are dangerous and unpredictable creatures, and therefore a 100% guarantee cannot be given. It is impossible to guarantee that all sharks will be deterred under all circumstances.
Since the inception of airbags in motor vehicles many lives have been saved by the invention, but it cannot be claimed that air bags save lives 100% of the time. With or without the protection of a Shark Shield, all sharks should be treated with respect and caution. Water sport participation in the presence of sharks is inherently dangerous. Any human activity in the water near sharks must always be considered as possessing a considerable degree of risk.
Like any piece of electronic equipment, the Shark Shield will not work effectively if not used in the correct manner, and if the units are not maintained correctly. The product instruction booklet provided with the unit must be read thoroughly prior to using the Shark Shield.
In April 2003, following the inquest into the death of a commercial scallop diver in South Australia, the State Coroner recommended that "...all divers diving in waters where there is the risk of the presence of sharks should wear a shark repellent device such as a Shark Shield or Shark POD..."
- Has the Shark Shield been proven to be safe to humans?
The field generated by the Shark Shield, when used in accordance with the instructions contained in the instruction booklet supplied with each unit, poses no danger to the user, to sharks or to the environment. The field can be detected if the electrodes come into very close contact with the skin.
Direct contact with, or very close proximity to the antenna, may cause twitching of the surface muscles of the skin, in time with the slow pulsing of the signal. The conductive field readily travels through seawater, it being a better conductor than the human body. Thus the field tends to surround the body rather than penetrate it. Scientific tests show that the type of signal generated by the Shark Shield is unable to pass through body tissues, unlike radio waves or microwaves that readily penetrate the body, and therefore it poses no health problems for users.
However, anyone with any health condition which could increase their sensitivity to the fields created by the Shark Shield should not use the device. Such conditions include heart disease, a history of heart attack, peripheral vascular disease, stroke, a history of fainting or epilepsy, lung disease, or if the user is on any prescription drugs that are administered for these conditions. People who have pacemakers or are pregnant must not use the Shark Shield and should also avoid swimming near any other person using the Shark Shield.
- Does the Shark Shield harm sharks?
From the tests conducted to date, the Shark Shield does not harm the shark. The majority of initial testing was carried out by a team of marine biologists at the Natal Sharks Board of South Africa.
Scientific tests, as well as observations, show the field emitted by the Shark Shield causes discomfort to the shark, which can eventually lead to muscular spasms. However once the shark leaves the area, there is no lasting detrimental effect to the shark.
- When should I turn on the Shark Shield?
Do not turn the unit on until you enter the water. Turn the unit off when exiting the water.
- Do I have to leave the Shark Shield switched on all the time?
Yes, when in the water. According to the International Shark Attack File of the Ichthyology Department of the Florida Museum of Natural History - see www.flmnh.ufl.edu/fish/sharks - 52.3% of shark attack victims did not see the shark prior to attack. Therefore do not wait to turn the unit on. Ensure the unit is turned off when you are exiting the water.
However, the unit must be switched off when inside a shark cage or in any other confined areas such as wrecks or caves. Also see "When should I turn on the Shark Shield."
- Who can use the Shark Shield?
Please see our product matrix for the suggested units for each activity.
- Can the unit be used by children?
The Shark Shield must not be used by children under the age of twelve years. The Shark Shield is a safety device, not a toy. It is deemed that children under the age of twelve, even with adult supervision, do not have the necessary level of maturity required to use such an electrical device, which, if not used correctly, will not give the level of protection to the user that it is designed to do.
Children above the age of 12 must be supervised by an adult to ensure that the Shark Shield is used correctly and in accordance with the instructions and warnings contained in the instruction booklet supplied with each unit.
- On which part of the body is the Shark Shield worn?
It depends on which unit you use.
FREEDOM7 - Is attached to the ankle via a neoprene casing. Both electrodes are encased in the 2 meter antenna.
SURF7 – The Surf unit is not attached to the body, it is mounted on the tail of the surfboard via a mounting board, deck grip can then be stuck to the mounting board, the 2 meter antenna that houses the electrodes then hangs out the back. The mounting board can be unscrewed so that you can recharge the unit or mount it on another surf board.
SCUBA7 - the main housing of the unit can be worn on the thigh (a strap is provided), in a BC pocket, or attached to the front of the BC via a BC strap or D ring. The antenna electrode is worn on the ankle, with the antenna protruding out the front, so that it rests on the fin. The pad electrode is secured to the back of the scuba cylinder via the BC securing strap.
- Do the electrodes need to be immersed in the water for a protective field to be created?
Yes, most definitely! Both electrodes need to be immersed in the water for a protective field to be created. In the case of the Freedom and Mariner units, both electrodes are encased in the antenna.
In the Scuba unit one electrode is encased in the antenna protruding from the ankle, whilst the other electrode is worn on the scuba cylinder.
- Does the Shark Shield repel any other creatures?
One of the distinct advantages of this unique electronic wave-form is that it only repels predator sharks and members of the Elasmobranch family including Rays and Skates. Elasmobranch animals all have Ampullae of Lorenzini.
Although both anecdotal, and some very limited tests on Crocodiles, show the Shark Shield wave form has an affect, considerably further testing must be conducted before any claim can be made or implied.
- Will I get an electric shock?
The Shark Shield works by emitting an electrical signal between two visible stainless steel electrode braids which are located at the top and bottom of the antenna.
To produce a protective electrical field of a significant size the electrical signal needs to be high in power. When accidentally placing your hand near or on the antenna the high power signal may cause stimulation of the surface muscles of the skin. This may differ for each person.
The amount of stimulation is minimal if accidentally touching the antenna while it is fully submerged. The reason for this is that the easiest current path for the electrical signal to flow between the two electrodes is through the water rather than through the user.
A higher amount of stimulation may occur if the user accidentally lifts one of the electrodes out of the water with their hand or other parts of their body. The reason for this is that the user then becomes part of the current path between the two electrodes.
- Keep the antenna submerged at all times.
- If using a Scuba or Mariner unit (for diving), then these must be worn with a wetsuit.
- If using a Freedom7 for scuba diving or snorkeling, to reduce the risk of the antenna accidentally touching your body then secure the initial length of antenna from the electronic housing to your fin. The method of attachment should be with something similar to a plastic cable tie. Do not use a metal fastening device or a system that significantly covers the antenna electrode.
- Anyone with a pacemaker, are pregnant, or has a health condition that could be effected by the electric field should not use the device. Such health conditions include heart disease, a history of heart problems, peripheral vascular decease, stroke, a history of fainting or epilepsy, or lung disease.
- How long does the battery pack last?
The battery with the FREEDOM7, SCUBA7 and Surf units will last up to 7 hours if fully charged prior to use. The lithium battery is rechargeable
- How do I know when the battery pack is getting low?
A solid green LED shows when the unit is operating normally. If the battery is running low alternate red and green flashing LEDs will be displayed, together with an audiable alarm.
- Can I "top up" the battery pack when it still has some charge left in it, or does it need to be fully drained?
Yes. Topping up the battery pack when partially charged will not damage the battery or lead to memory effect problems. However, any rechargeable battery benefits from being totally discharged every 6 months.
- How should I store the battery pack?
Always rinse your Shark Shield in fresh water and allow drying prior to storage. To obtain maximum life from the battery charge after each use and always store the unit charged.
- How can I test that the unit is working properly?
Holding either hand close to the antenna, i.e. less than 300mm (12 inches) away, whilst immersed in water and while the unit is switched on, is a handy way of checking the field. If the unit is functioning properly, the user should feel a distinct pulsing of the skin muscles of the hand. For surfers, being on the surface of the water and often in bright sunlight, this is the easiest way to check the units operation.
- What is the warranty period for the Shark Shield unit?
The Shark Shield has a 12 month manufacturer’s warranty, provided the unit is maintained as per the instructions set out in the Product Information Booklet supplied with the product. The battery pack supplied with the product, or sold as an accessory, comes with a 6 month warranty from the date of purchase.
As outlined in the Product Information Booklet, the warranty is only valid if the Manufacturers Warranty Certificate has been completed and returned. It is also a requirement that proof of purchase be supplied when making a warranty claim.
- Can I use the Shark Shield in estuarine environments?
Shark Shield is designed for use in seawater only.
The Shark Shield cannot be used in fresh or estuarine waters, as it will not establish a protective field in freshwater due to the water's reduced ability to conduct electrical energy.
- What is the depth rating of the Shark Shield?
The maximum depth of use is 45 meters.
- Does the field of the Shark Shield interfere with a divers hoseless air integrated dive computer?
From the tests conducted to date, no interference has occurred on the Uwatec range of computers. However, if wearing the Scuba Unit, the Shark Shield field has on some occasions (but not usually) interfered with the Suunto Vytec. This effect has not been observed when wearing any Freedom or Surf unit.
- What types of sharks does the Shark Shield deter?
All predatory shark species are repelled by the Shark Shield. These include Great Whites, Tigers, Zambezi (Bull), Mako, Oceanic, Grey Nurse, Hammerhead sharks.
Some sharks, in particular the bottom feeders, including Woobygong, Carpet and Port Jackson sharks, have their Ampullae of Lorenzini located under their snouts and as such have a diminished response to the Shark Shield wave form. A small number of sharks such as the Seven Gill shark have a diminished Ampullae so are less affected. The sharks that fall into these categories are in general, not considered dangerous to humans.
- What is the right shark shield for me?
Please see our product matrix for the suggested units for each activity.
Have more questions? Please contact us