Power cord in the water - danger, or not?

[Captain Pre-Capsize]

At my harbor it is common to see adults and children alike swimming around the boats at their slip. There are, I suppose, two hundred or so and most are plugged in to the pedestal at their slip that provides power to the boat. It essentially tops off the batteries but is 110 volts being slung from the pedestal along the lifelines of these boats and to the plug in the transom. Seems I read about an errant current being possible that turns the water into a real danger zone. Sound familiar to anyone?

[Bob Adams]

Danger yes. One mis wired boat, and they are common, and ZAP!

[Bill Griffin]

Darwinism at work. The marina owners could be at significant risk too! Early and rapid defibrillation might save a swimmer or two if they're lucky.

[Bill Griffin]

hmm. my smilies not workin

[Woxbox]

Ask one of those divers who clean bottoms for a fee about stray current. I understand they learn to sense it -- some sort of a tingling sensation or something...
It can also eat up a zinc prematurely.

[The Bigfella]

One of our Olympic swimmers was doing a demonstration about a month back in IIRC a relocatable pool of some sort - she got a zap - which was relatively low voltage - due to a wiring defect - was lucky not to drown and has suffered severe headaches and so on for a week or more since.

I believe a lot of apparent drownings are actually due to a relatively mild shock near marinas. May or may not be right on that though.

[htom]

If all of the equipment is installed correctly and has not failed -- but that's not possible.

[paladin]

A person with dry skin has a relatively high skin resistance and it takes a good voltage to give a nasty shock.....
In the water your skin is saturated.....distilled water is a non-conductor, but the tiniest bit of salt or pollutant in the water makes it conductive, and with saturated skin it requires a far smaller voltage to give the same shock.....and something that you would not feel in dry air will kill you in very short order in the water....

[Jay Greer]

The main problem is from parasitic flow and degradation metal components of boats that are not properly protected by adedquite zincs.
Jay

[WX]

OH&S in this country states that on building sites power leads must be something like 2 metres off the ground. As for power leads to boats in marinas I doubt it would be legal for a lead to be in contact with the water....a highly dangerous practice in my book.

[Noah]

I believe that DC is more deadly than AC when in the water. AC takes a bunch of volts to kill, but there are reports that folks just freeze up and drown with very low levels of DC.

[Gary E]

Is it a good idea to drape the power cord in the water?.. NO
Is it a danger to someone swimming? NO
Anyone IN the water is allready grounded.. and safe

Only someone standing in a puddle of water, holding onto a water pipe. or other GROUNDED item and THEN grabing the 120 v wire does have a jolt comming...

You people worry waaaaaaaaaaaay to much...

I'll give you an example...
Long ago when I was a kid in the early 1950's and the family was on vacation in Fla we were having breakfast and I was barefoot and standing on the wet or damp concrete floor of the house and touched the toaster and got a shock... Dad just reversed the way it was plugged in and no more shock...

WHY did this work??
Because the toaster frame was connected to one side of the circuit... WHICH side was determined by which way it was plugged into the wall.... By reversing the plug the grounded side became the frame of the toaster...And now even when the toaster was toasting, all the current went to the return path that the power companies system required. No shock could ever be felt since I was now "out of the loop"

[willmarsh3]

I once accidentally dropped the end of the power cord in fresh water. Nothing happened. But I immediately unplugged it and pulled it out. I can't discount the possibility of stray DC flowing through the cord even though it is AC.

[rbgarr]

There a MANY examples of electrocution (immediate and fatal) suffered by swimmers in marinas. It's an insane thing to do and marinas should absolutely ban it:
http://tinyurl.com/22f3qa

http://boatingsailing.suite101.com/article.cfm/mitigate_electric_shock_drowning

[Gary E]

I believe that DC is more deadly than AC when in the water. AC takes a bunch of volts to kill, but there are reports that folks just freeze up and drown with very low levels of DC.

Did you ever touch both terminals of the 400 Amp Hour 12v battery in your car?

If you dont want toi waste time lifting the hood, stick your finger in the cigarett lighter socket... feel anything??

On second thought, lift the hood, check your oil, water in the coolant overflow bottle? window washer fluid ok???
How bout the belts and hoses... they look good?

[Bob Adams]

Is it a good idea to drape the power cord in the water?.. NO
Is it a danger to someone swimming? NO
Anyone IN the water is allready grounded.. and safe

Only someone standing in a puddle of water, holding onto a water pipe. or other GROUNDED item and THEN grabing the 120 v wire does have a jolt comming...

You people worry waaaaaaaaaaaay to much...

I'll give you an example...
Long ago when I was a kid in the early 1950's and the family was on vacation in Fla we were having breakfast and I was barefoot and standing on the wet or damp concrete floor of the house and touched the toaster and got a shock... Dad just reversed the way it was plugged in and no more shock...

WHY did this work??
Because the toaster frame was connected to one side of the circuit... WHICH side was determined by which way it was plugged into the wall.... By reversing the plug the grounded side became the frame of the toaster...And now even when the toaster was toasting, all the current went to the return path that the power companies system required. No shock could ever be felt since I was now "out of the loop"

Sorry Gary, you are dead wrong. Example, boat A has reverse polarity (common) and boat B next to it has proper polaritiy and you swim between them. Some of the voltage is disipated into the water, but the properly grounded boat provides a better path. I wouldn't reccomend it. If there were no incorrect wiring, there would be no problem. But think real world.

[George Roberts]

Gary E ---

Provides explains the situation correctly.

I suspect that people who have problems with stray currents in the water are those who are entering or exiting the water. They touch a piece of metal on the boat with a hand; the water with a foot. The potential difference disrupts their internal electrics. And ...

[Gary E]

Sorry Gary, you are dead wrong. Example, boat A has reverse polarity (common) and boat B next to it has proper polaritiy and you swim between them. Some of the voltage is disipated into the water, but the properly grounded boat provides a better path. I wouldn't reccomend it. If there were no incorrect wiring, there would be no problem. But think real world.

IF what I said was wrong...how do you prove it? Remember, once current goes to ground, everythng connected to ground has zero potential relative to ground. Also isnt ground the normal path back to the power plant?

How are you going to prove that what you said is correct?
By not swimming in anything other than a farmers stock pond?

[donald branscom]

Question #1 Where are the parents?

The marina should have a sign that says Absolutely no swimming.

If the harbor master does his rounds and sees a power cord in the water, he should immediately inform the owner to get it out of the water. Of coarse many boat owners only show up once a year. They don't care. When I lived on my boat I saved many boats from disaster. Getting up at 3 AM to fix a roller furler that comes undone,boats that have the bowsprit over the dock and the boat is slamming up and down breaking the bowsprit off of the boat, boats with rotton dock lines going adrift into other boats. Halyards banging on masts 24/7 untill hardware starts appearing on the deck, Families coming down in the summer talking very loud at 7AM telling all thier business, Families getting drunk and leaving the dock carts full of trash. The live aboards usually can't wait untill summer is over and the trashing of the marina stops.

One time two young men came down to thier boat one summer and were too lazy to carry thier porti potty up to the bathroom to empty it. They were dumping it overboard IN THE MARINA. A man walking by caught them and stopped them and said it loud enough that everyone in the marina looked over to see what was going on.

[Gary E]

Question #1 Where are the parents?

The marina should have a sign that says Absolutely no swimming.

If the harbor master does his rounds and sees a power cord in the water, he should immediately inform the owner to get it out of the water. Of coarse many boat owners only show up once a year. They don't care. When I lived on my boat I saved many boats from disaster. Getting up at 3 AM to fix a roller furler that comes undone,boats that have the bowsprit over the dock and the boat is slamming up and down breaking the bowsprit off of the boat, boats with rotton dock lines going adrift into other boats. Halyards banging on masts 24/7 untill hardware starts appearing on the deck, Families coming down in the summer talking very loud at 7AM telling all thier business, Families getting drunk and leaving the dock carts full of trash. The live aboards usually can't wait untill summer is over and the trashing of the marina stops.

One time two young men came down to thier boat one summer and were too lazy to carry thier porti potty up to the bathroom to empty it. They were dumping it overboard IN THE MARINA. A man walking by caught them and stopped them and said it loud enough that everyone in the marina looked over to see what was going on.

Boy are YOU a party pooper... no swimmin... sheesh...I spose you had kids that obeyed YOU all the time???

As for the rest of your rant... it has nothing to do with ELECTRICITY...
Learn about it...

[WX]

Anything over 32 volts dc is considered dangerous. I'm not an electrician but I would imagine it would depend on the amp/hours....unless of course you have a pacemaker.

[Kim Whitmyre]

I've been in at my slip once, scrubbing the hulls: I warned the two marina workers who were sanding a boat close to mine to be careful with their cords :eek: No tingling sensations. I have read that you can take a meter, put the ground lead to the shore ground, and then put the positive lead into the water to do a check on stray voltages.

[paladin]

If your skin is wet I can kill you with a 9 volt battery......and if I get really mean and sneak into your bedroom at night, especially after you're hot and sweaty I can do it with a AA cell and not leave a mark....very low voltage, and very low current...better safe than sorry.

[The Bigfella]

We've rebuilt Grantala from the hull up on the water using 240 volt power tools all day long - via the genset or the inverter. The rule is to tie the power lead to a ventilator, so that if you go in to the drink with a tool, it unplugs itself on the way. There are too many idiots who come through pushing out a wake to not take it seriously. The genset runs through an earth leakage device for additional safety.

http://www.imagestation.com/picture/sraid225/p8f0fc68f3ffc63bc4531dc1ca55940a4/e8b83d6b.jpg

[WX]

I think when it comes to stuff that can kill you very quickly and or unpleasantly...don't bugger about.

[Tom Lathrop]

Gary, George,

You guys are DEAD wrong. Being in the water is being in the middle of a conductor. Your body can certainly short out part of the water and get a shock.

The toaster episode is an example of misunderstanding the situation. It's also an example of why the outside metal parts of all appliances are required to be tied to ground through a separate green conductor. That toaster must have been build in the dark ages before UL required such a ground lead. Unless you break off the ground pin, it is not possible to reverse the plug on modern metal cased appliances.

[WX]

Some years back a couple were working on the their careened boat in the shallows. She was doing some sanding and dropped the sanding in the water...she was wearing seaboots and was quite safe until she picked it up.

[Andrew Craig-Bennett]

snap.

1974. Mike McMullen's wife was sanding the topsides on Three Cheers; dropped the sander in the water and was killed when she tried to pick it up.

Mike entered that year's OSTAR none the less and was lost at sea.

[Gary E]

Gary, George,

You guys are DEAD wrong. Being in the water is being in the middle of a conductor. Your body can certainly short out part of the water and get a shock.

The toaster episode is an example of misunderstanding the situation. It's also an example of why the outside metal parts of all appliances are required to be tied to ground through a separate green conductor. That toaster must have been build in the dark ages before UL required such a ground lead. Unless you break off the ground pin, it is not possible to reverse the plug on modern metal cased appliances.

Tom,
You are wrong... learn about electricity, how it is generated and the disributation system. Earth, or ground is one of the conductors back to the origin or power plant. So standing on the ground in a puddle of water is just the same as holding onto the ground wire in a electrical system, IF it's wired correectly.

The toaster example proves it, when the plug was reversed, the metal outside of the toaster was changed from the hot side to the ground side.

As for the newer plugs where you have a wider spade that prevents swapping connections and a seperate grounded pin, yes, today that helps, but only if the house was wired correctly to start with. How many of you know hack electricians who dont know how to wire things acording to hoyle? Lots if you actualy inspect their work. And if you dont know, how are you going to tell a good job from a shoddy one?

As for the real problem here, it's knowledge... you cant "see" electricity so many dont understand it. I sugest you ask a 8th grade electrical shop teacher how it works.. If you want to delve into it on your own start here...

http://www.howstuffworks.com/power9.htm

http://www.howstuffworks.com/power9.htm

http://en.wikipedia.org/wiki/Electricity_distribution


Bottom line... IF you dont KNOW... stay safe or use hand tools.

[Gary E]

Some years back a couple were working on the their careened boat in the shallows. She was doing some sanding and dropped the sanding in the water...she was wearing seaboots and was quite safe until she picked it up.

She provided the return path for the power... you expected something else?

[rbgarr]

... and you can never know in a marina if all boats are wired correctly, so don't swim in marinas.

[Gary E]

snap.

1974. Mike McMullen's wife was sanding the topsides on Three Cheers; dropped the sander in the water and was killed when she tried to pick it up.

Mike entered that year's OSTAR none the less and was lost at sea.

That's sad... but just another example of someone not knowing how electricity works.

[Ian McColgin]

The electrical theory advanced by the folk saying it's safe to swim around marina's is incredibly off-point, but it must be said that drowning by electro-shock paralysis is enough different from electrocution that perhaps they were mislead about the phenomenon. The phenomenon of drowning is certainly different from the common boat hazard of using power tools in proximity to water which can lead to a fatal shock, not drowning.

On reading the articles what we see is a theory - I'm not fully sure how well documented it is - that the drownings in question were caused by electro-shock induced paralysis. These drownings are said to be post-mortum indistinguishable for simple drowning - death by water in the lungs - with no obvious correlative signs like blunt force trauma to account for the victem's inability to get to the surface and breath normally. The article cites witness statements that relate to electric shock and the fresh v salt water discussion makes sense.

I must say I never thought much of this but I'm not around fresh water much, don't hang at marinas, and surely don't swim in places where boats are moving about a lot. So what do I know.

Makes sense to keep an open mind on this, given the huge number of both boats and marinas that have screwed up wiring.

[Bob Adams]

Palidin, please respond to Gary before he gets someone killed. It's all about the path of least resistance. Water is an imperfect conductor. The hard connection to the shore power will be better. If you are between the fault and the better ground, well. I wouldn't want to be.

[Tom Lathrop]

Tom,
You are wrong... learn about electricity, how it is generated and the disributation system. Earth, or ground is one of the conductors back to the origin or power plant. So standing on the ground in a puddle of water is just the same as holding onto the ground wire in a electrical system, IF it's wired correectly.

The toaster example proves it, when the plug was reversed, the metal outside of the toaster was changed from the hot side to the ground side.

As for the newer plugs where you have a wider spade that prevents swapping connections and a seperate grounded pin, yes, today that helps, but only if the house was wired correctly to start with. How many of you know hack electricians who dont know how to wire things acording to hoyle? Lots if you actualy inspect their work. And if you dont know, how are you going to tell a good job from a shoddy one?

As for the real problem here, it's knowledge... you cant "see" electricity so many dont understand it. I sugest you ask a 8th grade electrical shop teacher how it works.. If you want to delve into it on your own start here...

http://www.howstuffworks.com/power9.htm

http://www.howstuffworks.com/power9.htm

http://en.wikipedia.org/wiki/Electricity_distribution


Bottom line... IF you dont KNOW... stay safe or use hand tools.

Actually Gary, I have a masters degree in electrical engineering. People have been caching fish for a long time by sticking the two leads from an electrical source in the water and turning on the juice. It's illegal unless you are with a Gov. wildlife service or other permitted research org.

If you are so certain of your position you should put the two leads from an AC outlet in the water at, say 10 to 20 feet apart and jump in between them. Make out your will first. Might not kill you but you won't do it again.

It's not always what you don't know that gets you. It's what you know that ain't so.

[P.I. Stazzer-Newt]

Palidin, please respond to Gary before he gets someone killed. It's all about the path of least resistance. Water is an imperfect conductor. The hard connection to the shore power will be better. If you are between the fault and the better ground, well. I wouldn't want to be.

Why bother, the world is not short of idiots.

http://www.rickly.com/as/electrofishing.htm

[Gary E]

Tom..
THe wires on the poles are the power supply, everyone see's them...
What is the RETURN PATH to the power plant?


Ok... ALL OF YOU ....

GET THE Hell OUT OF THE WATER...

[Tom Lathrop]

An average resistance for a body of water is in the order of 200 meter-ohms, some less, some more. Because of the dissolved minerals (salt, etc) in your body, its resistance is less than that. Placing a living body in the water that is carrying a current will allow some of the current to pass through the body because its opposite ends are connected to water at a different potential. Ohm's law
I= E/R. The current in the water that has resistance creates a potential between any two series points in the water. Short that out with your body and you get current flow in you body.

You are parallel path to the current flow and some current, depending on the resistance of your body relative to the surrounding water, will flow through you. Elementary.

[Gary E]

You did not answer the question

What is the RETURN PATH to the power plant?

[Tom Lathrop]

Gary,

It would be best to let this one slide. It would save greater embarrassment later.

[Gary E]

Who's?

Are you sugesting there is no return path to the generator?

[WillW]

Actually Gary, I have a masters degree in electrical engineering. --- :D

[essaunders]

One isn't needed, thanks to the magic that is three phase power.

[Tom Lathrop]

Who's?

Are you sugesting there is no return path to the generator?

Gary,

Your latest question is unrelated to and a couple layers of complexity removed from the original problem.

[Gary E]

Ohh??

Please explain that ...

[Gary E]

As a reminder to the original question...

Power cord in the water - danger, or not?

It's not a problem... unless there is a open path from the current carring wire directly to the water... And IF that were to occur the breaker will trip... if the bereaker does not trip, the wire will get hot... if that still does not trip the breaker or blow a fuse, the wire will melt...

Is it safe to swim in the area?? YES..

[WillW]

Gary, as a thought experiment, please consider taking a bath, then asking your spouse to throw a 110 v. radio into the water.

The radio will likely short out and the breaker will trip, after killing you. I believe that most breakers are time-delayed so that they can sustain transient faults. On the other hand, a Ground Circuit Fault Interrupter (GCFI) should trip instaneously, which is why they're electrical code for bathrooms, etc.

Tom:

I'm assuming that the danger with marinas (30 amps too!) is that anyone / anything in the vicinity of a live power cord could become a conductor as the live side shorts to ground or neutral.

[Tom Lathrop]

Gary,

I quit. You may proclaim yourself the winner of this argument.:D

To an audience of one.

[Gary E]

EE masters... ehh ??
and either cant or wont explain it....:D

[Tom Lathrop]

Tom:

I'm assuming that the danger is that anyone / anything in the vicinity of a live power cord could become a conductor as the live side shorts to ground or neutral.

I've seen this in operation myself where a boat pulled away from the dock and almost pulled the power cord into the water. Given that most of the marine power cords are 30 A, that's more than enough to be wary.

Will,

Current leakage from power cables, buried and in the air, is a constant source of problems for both electric companies and users. GFCI's (Ground Fault Circuit Interrupters) are routinely used to prevent damage from sources of leakage. Damage can be to people or equipment. The current toward the user in the hot wire and the current back to the source in the neutral wire should be exactly the same. Any leakage from the hot wire to ground at the user's site will trigger the GFCI and open the circuit. There are many ways to cause this unbalance leakage and you will be one of them if you come in contact with any part of the hot circuit and ground at the same time..

Electric circuits around marinas and on boats are not always as good (probably never) as they should be. Current leakage into the water from a multitude of sources on the boats or in the power system can generate leakage current back to the power source through the water instead of over the neutral wire. A GFCI near the source or an isolation transformer near the user load are the most effective ways of preventing this. There can still be some current in the water below the threshold required to trip the GFCI though and this can cause corrosion to metallic parts of the boats. 5 milliamps for GFCI threshold rings a bell.

[Tom Lathrop]

EE masters... ehh ??
and either cant or wont explain it....:D

Your weapon of choice in argument worked really well for Samson against the Philistines but is not working for you.

Sorry, the Devil made me do it:rolleyes:

[erster]

I don't got no masters degree in lectric cords going in the water cept the last time it happened , the breaker blew on the dock and the fancy Hubbell end turned green the next week and did not work right. Of course this happened in salt water. What happens in freshwater, propably stays in freshwater, though and may not be the same scenerio. So Gary is probably half right by staying out of freshwater..

[Gary E]

Will,



Electric circuits around marinas and on boats are not always as good (probably never) as they should be. Current leakage into the water from a multitude of sources on the boats or in the power system can generate leakage current back to the power source through the water instead of over the neutral wire. .


ok... now what's that path again??

[WillW]

Thanks, Tom.

I'm a relatively new boat owner, and frankly the casual attitude towards electrical power around the water frightens the s*** out of me. The marina power cords around here are 30 amps, which I believe is literally enough to kill a moose.

[paladin]

as stated above...distilled water does not conduct if it is pure...but stick your finger in it and natural salts and oils will contaminate the water....fresh water conducts, not as well as salt or brackish water, but once the human body is in it there are more salts in the body to make it more conductive.....
as an example.....take a small piece of copper, about 2 inches square, and a piece of zinc, same size. Attach the metal to the two leads of a milliampere meter, center scale perhaps 20-25 milliamps. drop the two leads in the water, once in fresh, once in salt, and watch the meter go off center.....basic battery...the water is acting as an electrolyte....an ounce of each metal as a thin foil in the water in the Chesapeake bay will cause a current of about 20-30 milliamps to flow....you can actually light an led like this.....
The resistivity of sea water, measured in ohms per square cm, is:
Pure water...........20,000,000 ohms
Distilled water........5,000,000 ohms
Rain water................ 20,000 ohms
Tap Water...................3,000 ohms...approximately
River water.....................200 ohms
Sea water, coastal.............30 ohms
Sea Water, open sea..........20 ohms

You can measure stray currents in your boat....take the Volt/ohm/meter, set it for resistance, touch two different pieces of metal inside the boat that are bonded to gether and grounded...and watch the needle jump......

[jimmy]

I used to be certified in Electrofishing, that is catching fish with a unit that was basically the equivalent of sticking two wires in the water as was mentioned earlier. One bit of information that is relevant is that electofishing only works in fresh water, NOT salt water. The simplified reason is that fish (and other animals including people) are better conductors of electricity than fresh water, but animals are not better conductors than salt water.

I'm not saying it is safe to swim in marinas, or that there aren't ways of getting shocked at a marina. A marina isn't the best choice of swimming location for a variety of reasons aside from electricity. Although it might not be as dangerous as some people think, it's hard to imagine how power cords in the water could be considered safe.

[jimmy]

ok... now what's that path again??

I'm not an electrical engineer, but I don't think that a path back to the power plant (through the neutral wire) is necessarily required. Electricity is also quite happy to go to ground. It is possible for a boat to be wired incorrectly so that the AC ground is connected to the DC ground which is often connected to the engine/propellor so that any boat wired in this way is a path for current in the water. I've heard it is also possible for this to happen with non-marine battery chargers. Now if the leaky circuit has a ground fault breaker, it trips and everyone is safe. If the leaky circuit doesn't have a ground fault breaker it will depend on the resistance of the path the stray electricity finds. If the resulting current is more than the breaker on the circuit, it will trip the breaker, if not you will have current flowing through the circuit.

I'm not sure how often this actually happens in marinas. There seems to be a lot more stray current in the water than can be explained by all the bits of dissimilar metals in the water.

As for how you get hurt from this stray current, that might take a very special set of circumstances, but I'm still not sure I would call it safe.

[Tom Lathrop]

The resistivity of sea water, measured in ohms per square cm, is:
Pure water...........20,000,000 ohms
Distilled water........5,000,000 ohms
Rain water................ 20,000 ohms
Tap Water...................3,000 ohms...approximately
River water.....................200 ohms
Sea water, coastal.............30 ohms
Sea Water, open sea..........20 ohms
..

Chuck,

I'm sure it was just a brain fart and you know this but resistivity is measured in ohms per cubic volume not per square measure. Turns out that the resistivity is independent of the size of the cubic volume and ohms/cu cm is the same as ohms/cu m or ohms/ cu mile. Those numbers are just averages and vary a lot.

[jimmy]

The marina power cords around here are 30 amps, which I believe is literally enough to kill a moose.

That's why you never see moose swimming in marinas. Kidding aside, 30 amps is more than enough to kill a moose. As somebody already indicated, the current required to kill somebody is probably in the milliamp range, however, it has to be in the right place, the heart. I'm not convinced you could kill somebody with a AA battery, but you will notice that those automatic defibrulator machines do not need to be plugged in and aren't very heavy so can't have much of a battery. They work by stopping the heart and if they weren't programmed to be foolproof, they could easily kill somebody (or a moose).

[paladin]

I know....I was working something in my head...(I wus up until 2 a.m.and fulla pain pills) and trying to work the cubic foot volumes etc and couldn't remember precisely what the data was on the use of the ohmeter/vom....these were all averages of the water around the Chesapeake bay the water which is brackish and not entirely good salt......and what was running through my mind was the corrosion problems with dissimilar metals.......I was a couple hundred yards from some power lines in the old neighborhood and we put up a 100 foot commercial tower...and three guy wires.....when we attached the last cable I was knocked on my fanny...we could run an ac voltmeter with the probes 3-4 feet apart and measure 110 volts on the standing wire from induction....
anyway....hopefully the next time the weenie cuts on me hopefully they won't gimmee the pills...the damn things make me sick, can't sleep, can't think straight, I want my mommeeee.......

[donald branscom]

Boy are YOU a party pooper... no swimmin... sheesh...I spose you had kids that obeyed YOU all the time???

As for the rest of your rant... it has nothing to do with ELECTRICITY...
Learn about it...

Yes I am a party pooper. I would let my kids swim in swimming pools or lakes.
The other things I mentioned are about people not following rules and not taking care of things that can affect others. Safety concerns.

[donald branscom]

Thanks, Tom.

I'm a relatively new boat owner, and frankly the casual attitude towards electrical power around the water frightens the s*** out of me. The marina power cords around here are 30 amps, which I believe is literally enough to kill a moose.

One AMP will kill you. You can look that up.

The problem is that water IS GROUND. If you get between the voltage and create a path to ground you will draw the current thru YOU.

EXAMPLE - Like if you were welding and the ground clamp was on dirty oily metal and you struck an arc and your body was touching the metal,your body may be a better path to ground than the ground wire. You would get electrocuted.

[Kim Whitmyre]

This isn't totally on topic, but when I built a house in the Berkshires with a steel roof, I read up on grounding such. The author was an engineer who did such work on transmission towers in Canada. One of the factoids I picked up was that .75 amp will fibrillate your heart=dead if someone does not de-fibrillate you quickly. He said 1 amp would jolt you, but not fibrillate you. The higher amperage must bring you back to life :p right away!

[donald branscom]

This isn't totally on topic, but when I built a house in the Berkshires with a steel roof, I read up on grounding such. The author was an engineer who did such work on transmission towers in Canada. One of the factoids I picked up was that .75 amp will fibrillate your heart=dead if someone does not de-fibrillate you quickly. He said 1 amp would jolt you, but not fibrillate you. The higher amperage must bring you back to life :p right away!

Very interesting. I have also read that the more times someone has been shocked the more resistance they have.

[WX]

She provided the return path for the power... you expected something else?
Reply With Quote

NO, she died...that's what I expect would happen.

[paladin]

Donald...you can be killed with 1 milliamp...that's one thousandth of an amp.........in certain sectors of Europe it was a favored assassination technique....

[Woxbox]

TUESDAY JULY 26, 2005
A 19-year-old Jessamine County woman drowned Monday at Scott's Creek Marina at Cave Run Lake after diving off a houseboat into water that was charged with electrical currents, according to Rowan County Coroner John Northcutt.


Anybody want to tell this woman's family it can't happen?
http://www.mikeholt.com/newsletters.php?action=display&letterID=47

And another one:
http://www.co.multnomah.or.us/sheriff/river_patrol/Winter_2005.pdf

[Kim Whitmyre]

So, how do you, or pros, clean the bottom in a slip? It's done all the time, as far as I know. Do the pros test the state of the water?

[The Bigfella]

So, how do you, or pros, clean the bottom in a slip? It's done all the time, as far as I know. Do the pros test the state of the water?


Water blaster

[Ian McColgin]

As I read the reports, freshwater marinas are more a hazard than salt. The hazards are transitory, depending upon cause with things like faulty air conditioning wiring being more likely to exist for a very short time while the ground faults that cause tickling around some marinas are more intractable. Most inwater boat cleaning is done in salt water on bigger boats, which cuts the risk to pros, and most transient currents are small enough that they are barely perceptable, much less lethal. Still, were I in the biz in freshwater, I'd only work on boats with the shore power disconnected and away from other sourses.

These problems are not at all unique to water. In Boston we investigated a number of ground faults in the local distribution system that energized manhole covers and occasionally killed a dog. On Cape a house near a transformer station had to have a veritable gauss cage buried around it to safe the plumbing.

Snearing at the hazard

[George Roberts]

There is a great deal of difference between harmful and harmless conditions.

If the source/sink of a stray current is an exposed fitting on a hull, being in the water a few feet away from the fitting should be harmless - the current density is too low.

On the other hand touching the fitting increases the current density
and may well kill.

Throwing a toaster into a bathtub kills because the bather is close enough to the source to be in the area of high current density.

Throwing a toaster into a swimming pool or lake is apt to be harmless to a swimmer 20' away.

[Kim Whitmyre]

Water blaster

By that you mean something like a high-pressure washer, Ian?

[The Bigfella]

Yep

[pipefitter]

Very interesting. I have also read that the more times someone has been shocked the more resistance they have.

I should be pretty resistant then. Not so much from the welding other than the constant zap from using continuous high frequency. It's relative to sweating and contortion welding around things at a reach.

Mostly working with Mr. Whillock on those damned old well pumps. After getting me bit a few times,I started just carrying the wiggy with me everywhere I went,to which I would hear, " I turned it off. . . dammit".
To which I would say, "I know you did". I can't even count how many screwdrivers he welded to pressure switches or motor end bells. The decider was the last time I got it,gave me a charlie horse and made me swear alot. Wet dirt,a gate valve and this old 10 guage UF sticking out of the dirt with bare ends that he swore had been dead for years was all it took. Nothing like grabbing something good like a valve when the wire happens to find it's way to your elbow.

So then,when is it that you know when you have developed enough resistance? I don't recall any of the instances becoming less displeasing in time,just less of a surprise. :D

[Bob Adams]

So, how do you, or pros, clean the bottom in a slip? It's done all the time, as far as I know. Do the pros test the state of the water?

With permission, I unplug the boats closest to mine while I dive on my boat. Failing that, I move my boat.

[paladin]

I never cleaned my boat in a marina.....and did not have a.c. on the boat until two years before it was sold....and then it was an isolation transformer for a charging system.....boat ran on 12 VDC.....But away from the marina...depending on location, I wore a dry suit, or just trunks and a "T" shirt....

[JTA]

bump