Is Your Boat “FISHY” – by Al Dampier

Or, what makes a boat fishy, or not fishy? I made this my mission to discover ‘why’ and this is part of my findings. I don’t know how many times that I have heard, or read: “It’s not the boat that catches the fish, it’s the fisherman”. I warn anyone that argues with me, you will lose that argument, at least in part.

As a career salmon troller, I used to think that I knew pretty much all that there was to know about the subject, until I started to create voltage tuned fishing lures. Since that time, my learning curve has gone straight up. A lot of what I have learned has come from the experiences of my customers and the best way to communicate my message is to relay those experiences to you. Here are just a few of many.

One chap fishing on the great lakes simply could not catch fish unless he had about 150ft of line out. I asked him to describe his boat to me. It was an older 20ft Starline aluminum boat with a single outboard. To make a long story short, it turned out that he had no hull anodes, which is not uncommon in fresh water, but he also had a broken wire that electrically connects the lower outboard leg (including zincs) through to his transom mount bracket and hull. He added one jumper wire and immediately caught fish close to his boat. Let’s call this “Starline”.

Six years ago, I sent some of my anodes to a Northern Ontario friend. He and 5 friends went out ice fishing for perch. Instead of attaching the anode to his hook or lure metals, like I asked him to, he put it 2ft up the line like a split shot. There were 6 anglers in a circle. For the first half of the day, my friend caught no fish, the 2 guys on either side caught very little and the 3 furthest away had decent catches. At mid-day, he removed the anode completely and all catches became equal for all 6 anglers. Call this “Perch 1”.

I wanted redemption, as this never left my head, so, two winters ago I made up some Mini Inline Tuners. This is a standalone voltage tuned item made of 2 dissimilar metals that only has to be placed close to the bait or lure. I sent out a few to complete strangers who were interested in testing them while ice fishing. The first result came from a father and son team. They had 2 holes drilled outside their ice hut. The one with the tuner caught 15 keepers and the other caught only few small fish. They were both using minnows for bait.

I sent another to a guy in southern Ontario and though, not as dramatic as the last results, the tuner more than doubled the production of perch, even after giving it to his fishing partner to use for part of the time. Call this “Perch 2”.

So, in the cases of “Starline” and “Perch 1”, it was obvious that certain metals by themselves can give off a negative signature and repel fish. This absolutely floored me, especially when one of them was my low voltage anode material, which I incidentally used on my Mini Inline Tuner in “Perch 2”. In both cases, the low rated metals (galvanic scale) like zinc and aluminum, can have Jekyll & Hyde characteristics, yet when configured with certain metals and in the right proportion, can give off a positive signature, like “Perch2”. This is backed up by another customer who simply commented; “My aluminum jet boat went from ‘zero to killer’ in 2 zincs”. In his case as well as “Starline”, the boat’s signature changed from a “negative” to a “positive” by introducing sacrificial anodes or zincs. My anodes in “Perch 1” remained a “negative”, but the radiating voltage changed to a “positive” by introducing a higher galvanic rated metal (cathode) for the anode to protect.

So far I have only discussed fresh water issues where I believe that more problems exist. That is because corrosion is so slow in fresh water that cathodic protection is often overlooked …….. but, the fish still know it! There are fewer issues for salt water anglers because protecting our boats from corrosion is usually important and this usually results in a fairly “fishy” boat, but not always. Let me put it this way. Have any of you anglers ever heard someone say something like; “My old boat fished way better than my new one”. Of course you have, or maybe you said it yourself. Those ocean fisherman that can’t catch fish with their boats, can’t catch fish even down at 200 feet. That shows how far the effects can travel and how sensitive the fish can be.

One of the most important things that you can do to make your boat ‘fishy’, is to bond all of the underwater metals together. Absolutely every underwater metal will give off its own signature. If your boat has 5 separated underwater metals, there will be 5 different signatures. If you think you know how to test your hull voltage, chances are that you are only going to test it by connecting your meter to only one of these 5 metals. This will give you a false sense of security. There are 4 more signatures that will most likely discount any good readings and you will always wonder why you don’t catch as much fish as the other guys. So, bond your boat and make it just one signature! Electrically connect (wire) all underwater metals including kicker motor, test each with an ohm meter against the boat ground (engine block) and zincs (anodes). I have seen the tilt rams on older Mercruiser outdrives get pinholed within a year in salt water. They have painted brass tubes and are attached with insulating rubber bushings. They should have jumper wires connecting both ends to the legs. They can give off a nasty negative signature. You should spend the time with an ohm meter testing virtually every possibility.

Another issue can be over zincing. Doing this may cause a similar effect as “perch 1”. Let’s say you have a basic fiberglass boat with a single outboard and no other underwater metals on the hull. Take a close look at the amount of surface area of exposed outboard metals that need protecting (cathodic protection). If the prop is painted, there is virtually none (externally). Now look at the amount of zincs present and their surface area. There is usually a trim zinc, possible recessed side zincs and a large zinc at the bottom of the transom mount. There is way more zinc than exposed outboard metals and the outboard itself is over zinced. The outboard probably has exposed metal internally, but also has engine block zincs and this is an unknown variable. If you have a stainless prop, as opposed to a painted aluminum one, it will help. I would still call it over zinced, but closer to a neutral signature and might fish ‘marginally ok’. A rule of thumb that I use is to have about 1 part exposed zinc to at least 5, and preferably 20 parts and more of exposed metals to be protected. So, keep that in mind when you are painting everything in sight and trying to prevent marine growth. That action may cost you some fish. Some antifouling paints may be water absorbent like the International XXX we used to use and that would be a good option because you get antifouling benefit plus the zincs still work with the painted metals and corrode as designed. Anything copper based will not react well with some metals, especially aluminum, check with paint manufacturers on this subject. Metal hulls or underwater parts can be a fisherman’s best friend. Ones that are sealed with paint will have no more benefit than a fiberglass hull. Stainless trim tabs can make a big difference to a boat. Add a small anode to each and connect both to the negative ground (bonding system). Just don’t paint them!

I am presently working with another chap from Quebec. He has a late model aluminum boat that was factory painted, completely sealing the bottom. He has always done well until he bought this boat, but now feels that he is in the lower 30% of others as far as catch rate. He has a 150hp main and a kicker. He does have a stainless prop on the main. I recommended doing the bonding as well as removing the large zinc from the transom mount, just to get his ‘zinc to metal ratio’ more in line. I also got him to make sure that all portions of the outboards are still protected by the remaining zincs. Outboard manufacturers would probably void any warranty, but they are only thinking of themselves as opposed to selling something that catches more fish. Compare that to my salmon trollers. I adjusted the amount of zinc used each year by how much was left at annual spring haul out. I tried to adjust it so that all zincs were depleted down to about 1/8th remaining. In that manner, nothing was over zinced. Depending upon which of my boats I’m talking about, this was between 30 and 100 pounds of zinc per year. To help you understand this in the most basic statement, if your zincs are not corroding, you are not creating a positive voltage field radiating from you boat. Once again, the zinc corrosion is way more obvious in salt water, but is still important to fishing in fresh water.

If you have a problem boat, contact me -



Viewers may have to copy and paste to their browser search.

* Berndt Kramer - Electroreception &Communication of Fishes -

* Daniel Nomura Master's Thesis - UBC_1979_A6_7 N65.pdf

* Brian Keeley's -




One of the most exasperating experiences of an angler's life is sitting in their boat, drinking coffee, and watching all of the boats around them catching fish. Now put yourself on a commercial troller doing the same thing! This is your livelihood. You have to catch these fish in order to feed your family!

That was me in my early years, during my first attempt to catch sockeye at an opening off of the Fraser River. If it wasn't for winter employment, that may have ended my salmon trolling career. I hung in there and started to research. I wanted to know, ... why?

One of the first 'eye opening' bits of information that is burned into my memory banks was of a study done on the Columbia River. A university (I believe), installed 2 large steel tubes in the river, applied positive voltage to one and negative voltage to the other. The results were that the returning salmon would only travel through the positive charged tube and not the negative one.

I learned about boat bonding systems as well as the application of positive voltage fields encompassing my arrangement of lures. I never left the dock after that without a Russell Black Box and I never 'sucked the hind teat' again.



Fish communicate, navigate, see with it, and some hunt with electroreception. There have been countless studies done on the subject. Here are just a few exerpts.



Brian L. Keeley. Philosophy/Neuroscience/Psychology Program, Washington University in St. Louis

“By the turn of the century, some began to suspect that, in addition to the ability to generate elec­tricity, some animals could detect the presence of electricity in their environ­ment. The electrosensory hypothesis gained credibility in 1917 when Parker and van Heusen discovered that the non-bioelectrogenic catfish, Ictalurus (Amiurus) nebulosus, could detect galvanic and direct currents. They did so through a series of experiments in which they presented blindfolded catfish with glass, wooden, and metal rods. The fish were able to detect the presence of metallic rods at a distance, but only reacted to the glass and wooden rods when they touched the surface of the fish. They went on to show that the type of behavior (to flee from or to approach and “nibble” at the rod) elicited by the presentation of rods could be modulated by changing the length of rod exposed to the water. Parker and van Heusen correlated the amount of exposed metal with the amount of galvanic current produced by the rods, and then repro­duced the behavioral results using direct electrical currents presented via electrodes placed in the aquaria with the catfish.

They go on to say: Notably, they do not posit an electroreceptive modality. Rather they propose that electric detection is mediated by the gustatory system, more specifically, by the taste buds. Their reasoning was that, electrical stimulation elicits feeding responses and these behaviours are typically mediated by the gustatory system. The head of the catfish is the most sensitive to stimulation, and most taste buds are found in the head, and “This assumption is completely in line with what has been known of human taste organs. For these are easily stimulated by direct currents of very low energy value”.





Professor Dr. Bernd Kramer

Universität Regensburg, Zoologisches Institut



“Being electroreceptive enables a fish to lead a secret, nocturnal life, undetected by diurnal predators. As no living organism is able to prevent weak electric currents leaking from its body it is of great selective advantage to detect these signals from a distance, even when the potential prey is buried under sand.”




Daniel Nomura – Masters of Science degree – zooligy dept. UBC.

He did his thesis aboard a commercial salmon troller in the Straight of Georgia.

After a summer of testing the voltage attraction of chinook and sockeye salmon, Daniel's conclusions were as such.

* Chinook were attracted and best caught when trolling wire voltages were at .5 volts and above.

* Sockeye were attracted and best caught when wire voltages were in the 1.0 volt range

* Both species showed obvious reduced catch rates when negative voltage values were applied.