esds the unit

Do shark shields or electronic shark defense systems work, you ask? Sure they do! Well it did last time we tested a similar product that produced an electrical field to keep the big “bities away” (an alternative to the ESDS, the Freedom 7 was reviewed here on this site in 2009 – see link ).

We have been using an electronic shark shield pretty much every second day in summer and occasionally even during winter for swimming protection since 2009 and we have not been eaten yet, although nearby sightings have been made. We are absolute believers in the principles that these work on and have done so since the practical first evaluation. We have just been given one that’s just been released to the market, the ESDS.



esds size matters      esds what you get


We have also investigated media reports that have suggested that people have been wearing a shark shield or defence system at the time of a shark attack. Regrettably, let’s face it, the Media like impact statements, such as “shark attacked whilst victim was wearing a shark shielding device”. What they don’t bother to tell you is that the people did not have it switched on. In fact there have been a number of cases where, once the unit was turned on, the shark quickly left the scene even though being in a state of frenzy at the time.
Now that we have got your interest, and with us being firm believers in the concept, let’s look at this latest related product to come our way for some in depth water testing (pun intended).
Supplied to us by Dive and Fish Australia, we are very keen to evaluate the latest Electronic Shark Defense System (ESDS) because we feel it will fill a niche market and specific purposes due to its much smaller size.  Indeed, some of the criticisms in our original review seem to have been dealt with by the new ESDS manufacturers.

esds on leg

This latest ESDS sent to us from (Australia) immediately surprised us because it is so compact.
As you can see, it is very small when compared to the previous one we reviewed, which has given it more attraction for the following applications:
•    Swimming – no long tails to shock you  nor weighty bulk to slow swimming actions
•    Body Surfing – no lengthy tail to curl around with wave action to shock you
•    Surfing – whilst there are surfing varieties available which attach to the board and hence cause drag, this one can be worn on the ankle and should protect you as long as your ankle is in the water to complete the electrical field.

We believe you could also attach it to the underneath of the board, but this could disrupt the flow lines of the board and may create a slight drag. We think that without much trouble the manufacturers could produce a longer belt so that only the Velcro belt and contacts were under the surfboard which would make drag negligible. If you then had the board ankle rope on, then you should still be in the field of the deterrent system if you fall off.
•    Diving – We believe the long tailed product may be better suited to Scuba Diving than the new ESDS, although we don’t really have much evidence to support this claim other than when we deliberately shocked ourselves with both units, we felt the  long tailed Freedom 7 provided a more intense shock.  We do believe the ESDS to be better suited to free diving than its competitors as the ESDS has the advantage of less restriction (tail) and/or bulk than similar products on the market.

esds note the led

Easy to charge and strap on with a vertically noticeable LED operational check light.
The claimed field of defence is similar to the products with long conductive tails, and that being true, we see it as being suited to a far wider generic application.

Supplied Specifications
ESDS Depth: 150 feet maximum
ESDS Dimensions: Approximately 2.65″W X 2.30″H X 1.15″L (enclosure only)
ESDS Weight: Approximately 7 oz, 198gm.
ESDS Power: Internal 3.7V Li-ion battery
ESDS Battery Charger: 6 VDC, 1.0 Amp wall transformer
ESDS Charging Time: Approximately 7 hours (new battery, varies over time)
ESDS Operational Time: 9 hours (in water)
ESDS Output: 120V to 200V pulsed proprietary wave form
ESDS Electrodes: 2 electrodes, each approximately 1″ X 1″ stainless steel mesh

Effective range is given as approximately 6 metres
The unit activates itself when you enter the water and deactivates when it is removed from water taking about 3 seconds to do so.
We took it for a 3.2 km swim and at no time were we accidentally shocked, and whilst you can easily see the green LED flickering as pulses are admitted, we intentionally touched the contacts to see just how strong the shocks would be.
We found the impulses to be on and off for approximately 3 seconds each phase, strong but not intolerable. We can confirm that the pulses do not influence other fish, finding that fish were all around us completely unperturbed. Our understanding is that only sharks have the electrical impulse receiver’s and that it causes only them to be uncomfortable with the electric impulse fields.

•    Extremely easy to wear
•    Stays in place
•    No danger of forgetting to turn on
•    Easily seen Green LED for operational check
•    Light weight and small (therefore you aren’t even aware of it being worn)
•    Good battery time
•    Additional blanking plug and an “o” ring is supplied for charging hole
•    Quality appears very high

•    Velcro fitting strap may not be quite tight enough to stop all movement on people with very small ankles or for some children without some form of packing arrangement.

We did find the ESDS (Electronic Shark Defense System) to be an extremely good asset to have when considering peace of mind against any possible shark attack. We figure that even though there are no guarantees against a shark attack by ANY manufacturers, we’ve seen the electronic pulse concept at work and hey, if it helps keep ’em away, then why not. It just provides a little more of that easily worn insurance.
In summary, we really liked the product and probably won’t be swimming again without it.
We believe that at the present time the ESDS is available online in an introductory sale on with a reduced price tag of $455 AUD.