Electric fish

[Frosty]

I never noticed it before,--well never put 2 and 2 together. A woman walking past my boat the other day said that always had lovely fish under my boat. I thought about this and she is right. My boat is and always has been surounded with fish.

Although this may be very nice I am now worried that they are attracted because of leaking currents from the stern end. I have no other attractions such as kitchen outlets there.

I use prop anodes at approx 1 per 10 months on a 21/2 inch shaft, I consider this normal, wouldnt you?

Ive read about fish being put off by stray currents but not attracted.

[masalai]

Load it up with a cattle prod/electric cattle fence charge for stunned fish dinner.

[lazeyjack]

Certain types fish most especially hammerheads hunt by electric impulse

But maybe your boat has a certain growth. which fish are attrected to
For sure they are not getting a charge from your boat Frosty ole bean
there are ships , say welding , which are passing 100,s ampseres
thsi whole thing bout electricity and electrolysis is very misunderstood, despite there being rheEms of stuff written abt it
My advise, tuck up in bed with NICE aSIAN GAL AND LISTEN TO THE NOISES COMING FROM THE SEABED

[Frosty]

Well these are definately not hammerheads, actually they are 'Archer fish ' those black and white things that squirt insects from off a twig. They are very curious and will squirt at your leg sometimes when working close to the waters edge. The missus eats em , easy to catch on bread.

But why my boat? do they like being caught and made into fish curry.

They are there for a reason and I cant fathom why.

Ive no growth and am freshly antifouled, they dont nibble at the boat just happily swimming around it.

Something fishy going on here!!!!

[masalai]

Don't hang it out for a pis, it may get shot off.

[Bergalia]

Don't hang it out for a pis, it may get shot off.


Too small a target....:D

[CDK]

Different sea, different fish, but the same phenomenon. Five or six fairly large fish were around and under my boat whenever I looked. Because the boat had technical problems I left it at the pier for many weeks and made only a few short trips. I assumed that the fish got used to the presence of the boat and liked the shadow.
Don't know the name, but local fishermen said that these fish are almost impossible to catch with bait because they distrust anything new...

[Fanie]

Ok, Frosty, it's quite logical why the fish are hanging around your boat. They feel safe since they know you don't know how to fish and secondly it seems to me your boat is a permanent structure that sits only in one place. I bet if you get someone to help you (who knows how to) turn the boat around it will confuse the hibby jibbies out of those fish.

And squirting at your leg... :D Kinky buggers aren't they ? I can only imagine what your leg must look like for them to find it that attractive :rolleyes: :D

Too small a target....
Are you saying these fish are taking blind shots ? So they instinctively know there is supposed to be a target but there isn't... Explains why they go fot the legs :D

Mmmm... Frosty, you are getting really positive information about the fish hanging around your boat eh ! I think the hull color plays a big role. I have to admit fish is too scared to even come close to my boat.

[Fanie]

Ahem... there are probably something in the area that attracts the fish. Fish may stay in a certain area ie a gravel bottom or a certain type of plant or algea in that area. If you go out with the boat I very much doubt they will follow. They probably are just curious about the movement on the water's edge and them taking a pot shot at you is just to see if it will bring food or not. You could probably condition them... each time they try their luck and you throw a piece of bread in there pretty soon you'll be able to take a shower right there... just bring bread :)

[Frosty]

These are smart fish ,even though their eyes are below the water they can make calculations so that they shoot at a fly for instance. They can calculate for the light refraction (if thats the right word)

They don't swim deep and they don't swim on the surface, just between 6 foot and zero. Some one must be able to fathom this out.

[masalai]

Maybe a comparison between the fish under your boat, chimpanzees, & American uni students could prove interesting and enlightening. Safie might well say the gene pool has deteriorated since their separation from the respective (European) mother countries & not enough cross pollination. C'mon tourists, do your bit for Americans intelligence levels inject some new genetic material into the mix.

[Kay9]

Put a small wire in the water. Run a multimeter from the block to the wire in the water. Anything over .05 Volts is bad. I use 1 pound of zinc per foot of wetted hull and they last 2+ years. I also adjust the in the water voltage when Im fishing for salmon. Silvers I keep the voltage at .05 and Chinooks I set the voltage to .075. It dose make a diffrence.

[Frosty]

Now we are getting some where. I done that K9, some time ago I think it was .o6. I even read a book but cant remember now.

As I mentioned I replaced the anodes in April and they are about done. I have 24 inch 4 blade props and stainless shafts,obviously going to make ctrickery.

I have a galvanised nail on a piece of wire and some copper on another.

I done all that testing stuff. Ille do it again today.

Strange actually because if I kneel down by the shaft and have one leg touch the motor and one knee touch the shaft I get a tingle,--but nothing on the meter( buy a new meter) yeah I done that?

I also have 2 batt switches pos and neg. Ive always prefered this way. What do you think about that? Fibre glass boat.

[masalai]

Frosty, are you on shore power? Is that circuit earthed somewhere? Then think who else may be on shore power with their earth the wrong way round, by which I mean the active is earthed and the neutral is switched on their boat, thereby making a circuit via the shore power, through their boat to the earth/neutral link line in your boat. Particularly if they use a non polarised plug/socket as opposed to the Australian standard which has the neutral link set by law/electrical standards for 240v ac.

No expert on this, but all non polarised plugs make me nervous for that reason. Do you get my drift or do I need to do diagrams to supplement my poor english?

[masalai]

. . . \ /
.. . . ! . as opposed to . I I . or . o o . getting the spacing is difficult.

[Kay9]

Batt switches sound ok. Not the way I do it, but shouldnt matter. The problem might not be your boat, it could be that your neighbors boat is placing high voltage in the water and your the other end of his high voltage annode, same effect but you have less controll. Also Masalai could also be correct if the shore power is not polarised correctly then that can cause the discharge. You might try your voltmeter both shore power pulgged in and unplugged. If this is the problem then I would think a power converter would solve your problem. However if your feeling enough voltage at your engine block to make your skin tingle then your likely putting more the 1 volt into the water....thats very bad.

Side note: I had a very bad mechanic install a new battery into a sailboat I used to own. The idiot wired it up backward. Pos to neg, in less then 2 weeks it ate through all the annodes and the shaft.

[Frosty]

Someone once told me that I should have the Eng block always connected to the neg batt terminal. He was quite a clued up septic. He said that many stray currents can end up there even RF and if nowhere to go will go into the anodes.

Sounds feesable.

Ok 240 V-- It wont make any difference to me I have no earth (third wire) I have no ground. Everything I buy here has 2 pins. Power comes in through 2 double pole switches and then to 4 distribution 2 pole switches,--one common neg bus and back out. The only metal bodied appliance I have is the microwave.

The reason I do this is because of Masalais explanation. I have seen so many times European boats with septics get the marina supply all confused. And I dont want to be someones ground if the marinas ground fails or even exists.

[StrandedMariner]

I use 1 pound of zinc per foot of wetted hull and they last 2+ years.

Is that with a steel hull, or FRP?

Just curious, cheers,
Andreas

[masalai]

see above - glass

[Kay9]

Steel Andreas. Belay my last when talking about wood or FRP.

[StrandedMariner]

Steel Andreas. Belay my last when talking about wood or FRP.

Thanks Kay9, you confirmed what I thought. I was curious because I am having a steel boat built, and want enough anode mass to last 2 years. Thanks!

Andreas

[Kay9]

I dont have a hard fast rule for wood or FRP except I get as much as I can fit on my shaft without putting her out of balance.

Frosty. the annodes is EXACTLY where you WANT stray current to go. The will sacrifice themselves in order to save the metal you dont want to lose. Of course Im certain you know this. You mentioned .06 volts before, thats not bad, and Im assuming your in salt water not fresh, as in fresh you dont want zinc, but rather magnisium (sp?) for your sacrificing metal. Some things that might make your zincs dissolve faster then mine are the salinity of your water. (Closer to the equator the more salty the water the more moving water will create an electric charge the faster your zincs dissolve) the temprature of your water. Warm water faster dissolve. Finally other power sources around your boat.

In Oregon, my water rarely gets above 60 F and our boats spend the ebb in allmost fresh water and the flood in salt. So you may not get the same performance on your zonc as I do on mine.

[Frosty]

A pound of zinc per wet square foot???????

Are your sure? not square meter?

Thats a lot of zinc and every 2 years? I like to hear from someone else on that one.

Yes I am in tidal flowing warm water just up a bit from the Equator. I suppose I should take that into consideration too.

[Kay9]

Perhaps im not clear.....A 40' steel boat should have 40lbs of zinc.

[Frosty]

Ah,--- thats better!!

[PI Design]

Can't help you Frosty, but I like the idea of fish that shoot insects. Sounds cool!

[Frosty]

What--???? youve never seen them on National Geographic programes on the telly ?

Again --yesterday,-- someone mentioned that I had my own private aquarium.

Anyone want a pic??

[masalai]

Yes with you in it too. and arrows to identify the fish from the floating debris

[PAR]

Move your boat to a different slip or area, preferably well clear of other boats. If the fish still linger it's your boat, if not, it's the environment your boat is in.

I've seen this happen on live aboards, that had goodies drain over the side from a galley sink. When was the last time you had a good look at the bottom of your boat?

[Frosty]

Cant move slip ,--marina is full and I take 2 slips being a cat.

No galley outlet at the stern. Dived on it last week,only slime --wiped off with a brush.

[Fanie]

Hi Frosty, does this mean you don't take the boat out to sail to somewhere ?

[Frosty]

Oh Oh --Im going to take it out after Christmas, I promise.

I dont sail --I dont have a stick.

The boat is 4 years old in Jan and has 175 hours on the engines.

Is that what you call--- light use?

[Fanie]

Up some pics of your rig, won't you ?

[masalai]

Frosty, I posted some dietary options on "Merry Christmas" You seem to have found your paradise? and are ready for whatever happens on the doom & gloom threads.