Diagnosed and repaired my Shark Shield

This article describes the steps I went through to discover and fix the issue in my Shark Shield. I will not encourage everyone to perform this fix. For those of you who don't have the time or patience to perform this repair, sending it in to Ocean Guardian for a trade-in may not be a bad option. However, for those of you who want to know how to check whether the electrodes on their Shark Shield are working correctly, this article may provide some useful info.

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While testing FishingAddict's Shark Shield by dunking it in salt water, I tested my own SS model C to compare. I was surprised to find my model C was not working. I didn't know because the unit turns on like normal, and goes through the boot up sequence like it should. And yet, it didn't give out any shock when submerged in salt water. Including my own unit, I had seen four units that had this same symptom. My unit had only been used 4-5 times, and I washed it thoroughly after each use.

To begin with, I decided to bite the bullet and bought a Shark Shield tester. I began inspecting the SS more closely, and measured the resistance of each electrode. It appeared that one of the electrodes had a much higher resistance than the other. I had decided to get to the bottom of it by tearing apart whatever necessary. I suspected it to be caused either by corrosion, or by poor connection somewhere. There seemed to be a crease on the wire, but I was not sure if it's anything concerning.


I proceeded to remove the main board, then removed the nut that locks down the electrode that has high resistance. That came off easily. The connector looked normal.


So I decided to remove the metal connector from its sleeve, which was injection molded onto the connector. It took some persuasion, but I was finally able to pull the sleeve back. Seeing nothing unusual, I then cut open the plastic wire cover to expose the wire itself. Immediately, the metal connector fell off. It's now obvious that the wire had been severed internally at the crease I noticed earlier. As you can use, the entire wire had been rusted.


I began cutting open more of the wire. After 3-4 inches, I was convinced that the entire wire had been rusted, so I stopped stripping more wires.


I was hoping the wire is salvageable. I used a fine wire brush and Corrosion-X to clean and remove the rust from the exposed wire. It turned out that the rust was only on the surface of the copper. After the exposed wire had been clean and checked for strength, I believed the wire could still be used.
This is after cleaning. Reinserted the wire into the connector. Because the connector is stainless steel, I knew I wouldn't be able to solder the copper to the stainless steel without making a big mess. I decided to fill the connector with aluminum foil to pack the connector tight against the copper wire. Roughed up the plastic with sandpaper to get a better grip.


I then applied 3M Marine Adhesive Sealant 5200 and pulled the sleeve down to cover the connector the way it was. Let the 3M adhesive dry for 24hrs.


Measured the resistance between the connector and the electrodes to make sure they are within the expected resistance. Put everything back the way it was.


And the final test using the Shark Shield tester.


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The following measurements should help you determine if your Shark Shield's electrodes are in good shape.
The resistance between one connector and the lower electrode (1 foot from the tail of the whip) should be around 1M ohms.

The resistance between that same connector and the upper electrode (1 foot from the head of the whip) should be around 1 ohm.


The other connector should have the reverse readings. Resistance between the connector and the lower electrode should be around 1 ohm. Resistance between the connector and the upper electrode should be around 1M ohms.
If your unit has similar measurements as above, your electrodes are physically sound.
(For reference, before I repaired the rust from my SS, the resistance in the corroded wire measured greater than 4M ohms between the connector and the bottom electrode.)

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As I mentioned, I purchased a tester to help test the Shark Shield. When I opened up the tester and saw what's inside, I was surprised and pissed that they charged me $62 for that thing. I had ordered some parts to put together a batch of 10 testers. When they arrive, I'll make them available at a more reasonable price. Stay tuned if you're interested in one.

 
Lucky,

Thank you for sharing your work. I can't wait to see feedback from those who actually understand electronics (I don't).

One question: do you recommend shark shields? I am considering plunking down $500+.

Well, I use it because my buddy FishingAddict (GWS attack survivor) swears by it. So far, I haven't seen any evidence that it doesn't work. Therefore, I would trust it with caution. I would say, if it gives you the warm fuzzy feeling that you're protected, by all means, get one. I have two

Thanks, this is great info. My really old SS (bought in 2011) has a lot of corrosion in that area, and I had gooped it, but never got it to work. I'll take it apart and do a more thorough inspection.

I have a new SS, but would like to fix the old one and get it setup to run from my FF battery, so it'll last all day and not start beeping after 5 hours....

As far as whether the SS works or not, there are several research papers listed on the SS manufacturer's website that give positive results. For my money the most impressive is this research paper:

https://cdn.shopify.com/s/files/1/0052/3862/0195/files/Effects_of_an_Electric_Field_on_White_Sharks.pdf

Table 4 of that paper deals with the results of their "dynamic decoy" experiments, which are the most relevant for kayakers. In that experiment, they towed a seal decoy on the surface with a SS in place. They performed 98 tows with the SS off and 91 with it on (otherwise, identical configurations). With the SS off, there were 16 breaches and 27 surface interactions, whereas when the SS was on, there were 0 breaches and 2 surface interactions. Those are impressive, real-world numbers, IMHO.

thanks for sharing, love the debug.  curios, what exactly is inside that box? some Schottky diodes, a capacitor, and a couple LEDs?

I'm thinking the pulses are short duration, high V, very low current.  Green light being inner to outer and Red opposite? the capacitors just to store enough energy that the LED will stay lit long enough for human eye to see it?

if you don't mind sharing, I'm very interested. 

I'm very interested in those DIY testers!  Were you also planning to show the internals for us to make our own?  From the shark shield manual it's saying it pulses at 150A voltage not specified which must be incorrect right?

I'm very interested in those DIY testers!  Were you also planning to show the internals for us to make our own?  From the shark shield manual it's saying it pulses at 150A voltage not specified which must be incorrect right?

what they don't say is the duration of the pulse, though they do say 0.6s between pulses.

sounds like they have a 150A current generator in the unit, and give a short pulse every 0.6s, so is short 1ms, 1ns?  I'd guess around 10-100ms+/-  may need to get my oscilloscope out and start playing...though I really don't want to ruin it, so maybe not

Although, I didn't like how much Ocean Guardian charged me for the tester, I don't want to publicly expose the device's construct because OG is a legit business. I will provide the info privately to those curious individuals.

I ordered enough parts to make 10 testers available for sale cheap. Maybe around $15 + shipping? Depends on my final cost for the materials. 2 of 10 are spoken for.

Although, I didn't like how much Ocean Guardian charged me for the tester, I don't want to publicly expose their construct because they are a legit business. I will provide the info privately to those curious individuals.

I ordered enough parts to make 10 testers available for sale cheap. Maybe around $15 + shipping? Depends on my final cost for the materials. 2 of 10 are spoken for.

I'd be curious to know what's inside if you wanted to let me know.  Also I'd be happy to send you $15 just for the help with shark shield stuff in general if you include your venmo in the private message.  I guess from my point of view watching lots of bigclivedotcom videos https://www.youtube.com/channel/UCtM5z2gkrGRuWd0JQMx76qA it's always cool to see how stuff works and I never have any intention of trying to compete with their business

Edit: I see you already sent the PM oops I missed this.  Thanks!

Bravo Ernest.  You are one smart techie guy!

Bravo Ernest.  You are one smart techie guy!

+1

Between you and NowhereMan, you guys should start a Shark Shield table of content section and reference all the mods and tests on that section (kind of like the annual salmon threads, but for Shark Shield instead  )