Electrocution swimming warning.

[Shortstop]

I just read an article in the latest BoatUS magazine warning of the danger of swimming in marinas that run 110v electricity to boats. They cited several instances of deaths of children recently. Often the person jumping in to save the person dies too. It talked about how some strengths kill right away while lesser strengths paralyze, causing drowning.
My club has taken a stronger position on enforcing the No Swimming rule in our association in the marina, but we still have a lot of swimmers, including me. I think I might rethink that - this article made it real clear, swimming near electricity should not be done. It went on to talk about how you can minimize risk with GFI's (Europe requires) and other ways, but thats not cheap and in addition to the clubs line, each boat needs protection.

[Heaven]

Originally Posted by Shortstop

I just read an article in the latest BoatUS magazine warning of the danger of swimming in marinas that run 110v electricity to boats. They cited several instances of deaths of children recently. Often the person jumping in to save the person dies too. It talked about how some strengths kill right away while lesser strengths paralyze, causing drowning.
My club has taken a stronger position on enforcing the No Swimming rule in our association in the marina, but we still have a lot of swimmers, including me. I think I might rethink that - this article made it real clear, swimming near electricity should not be done. It went on to talk about how you can minimize risk with GFI's (Europe requires) and other ways, but thats not cheap and in addition to the clubs line, each boat needs protection.

How is it that people can afford boats but not afford to GFI protect the electrical circuits? Boggles the mind.

[ishoot308]

Correct me if I am wrong but isn't it pretty much national code that all outlets near any water or water source and all exterior outlets be GFI protected...shouldn't the marina's electrical outlets all be protected by GFI??? Yes, I agree that boats before hooking up should also have their own GFI as a double source of protection but the main power source supplied by the marina should definitely be on a GFI.

Would anyone here run power to their dock that was not GFI protected...that would be insane and quite illegal!

Dan

[Shortstop]

Yeah - now that you mention it - I'm no electrician, but I know any electrical work near a pool/hot tub, bathroom sink, lake,...., should be GFI protected. I'm not sure if we are, but I will certainly check this weekend.

[jrc]

There are electrical codes for how boats and marinas need to be wired. Most modern boats with shore power have GFI on some of their outlets like the bathroom or cockpit.

The marina power connection to the boats usually are GFI only if it's a standard house plug, the round shore power plugs are not usually GFI. Remember GFI only protects stuff plugged into the GFI and plugs downstream from the GFI. It does not protect the marina wiring to the GFI.

So in order to protect swimmers from bad wiring in a marina, you would need a GFI on all the wires going from shore to the marina. I've never seen that done, I don't even know if it's possible.

There is no $20 GFI solution to this risk. The whole marina needs to be wired right to begin with and the wiring needs to be maintained. Maintenance is usually the issue. Stuff gets stepped on, hit by boats, beat up by ice, and corroded.

[ishoot308]

JRC;

I understand what you are saying, but I believe code would require a GFI from the main breaker box on shore that way if anything happens to the wiring going to the docks the GFI pops and you are safe. I am not an electrician so maybe someone who is can chime in.

I honestly cannot imagine any marina would ever supply power to a dock that is not GFI protected at the panel. This simply boggles the mind...

Dan

[jrc]

I'm not an electrician so I don't know all the codes. I've never seen a whole marina or whole dock GFI. Might be a good idea, might be impossible, might be be illegal.

I used to swim in the marina at Samoset all the time, usually between the dock and my moored boat. Never gave it much thought. But reading since then and remembering the wiring conditions there probably was some risk. And they didn't even have shore power for boats just lights on the docks.

Some of these big marinas with dozens or hundreds of boats, some over 30 years old, have to be even riskier.

[SIKSUKR]

This one has me scratching my head.There are stray voltages but I can't imagine a short to ground(water) with enough voltage to kill somebody that would not trip the breaker even without a gfi.Gfi's are really just a fast acting breaker.

[ishoot308]

Originally Posted by SIKSUKR

This one has me scratching my head.There are stray voltages but I can't imagine a short to ground(water) with enough voltage to kill somebody that would not trip the breaker even without a gfi.Gfi's are really just a fast acting breaker.

My guess would be improper or no grounding...

[NoBozo]

Maybe just enough Stray current to affect certain peoples heart rythm....like a Pacemaker in reverse. NB

[jetskier]

Actually it is a GFCI (ground fault circuit interrupter). There are three connections in the circuit: power, return, ground.

During normal operation all of the current flows between power and return. A GFCI measures the current on the power feed and the return. If there is an imbalance, the breaker flips. Essentially, it means that the current is going somewhere else to ultimately get to ground (potentially through you). A difference of about 6 ma will trip a GFCI...note that your normal breaker is 15 amps or 30 amps or more of current delivered across the power/return circuit.

A current of 60 ma or higher (at 120v, 60 hz) can cause ventricular fibrillation. This is measured based upon the touch point being a dry hand. If you are swimming, your body impedence is actually much lower and ventricular fibrillation can occur at a much lower current.

So, the bottom line is that everything should be GFCI protected and the GFCIs should be tested to verify that they are working correctly.

[SIKSUKR]

Actually,Jetskier is right on about how a gfci trips.A simple breaker trips by having too much current travel through it.That why I contend that having current high enough to kill going into the lake without tripping a breaker seems impossible except for a very brief moment.

[birchhaven]

I am probably way off, but I will throw this out there for someone smarter than me to finish.

When I was considering adding a irrigation system to my lawn. One contractor suggested pulling water from the lake. He said there is two ways to do it but only one right way. What he said is the wrong way is putting the pump in the lake, rather than on the land sucking it out.
He said that the pump in the lake can create an electrical field that will zap a swimmer even tho no electrical current would be going from the wires to the water, as in it is installed properly and there is no reason for the breaker to pop.
He could have been blowing smoke but he sounded like he knew what he was talking about.
Does any body else know what he was talking about? I wonder if a similar thing is happening with people swimming in a marina, since marinas tend to pack some serious amperage.

[codeman671]

Originally Posted by birchhaven

I am probably way off, but I will throw this out there for someone smarter than me to finish.

When I was considering adding a irrigation system to my lawn. One contractor suggested pulling water from the lake. He said there is two ways to do it but only one right way. What he said is the wrong way is putting the pump in the lake, rather than on the land sucking it out.
He said that the pump in the lake can create an electrical field that will zap a swimmer even tho no electrical current would be going from the wires to the water, as in it is installed properly and there is no reason for the breaker to pop.
He could have been blowing smoke but he sounded like he knew what he was talking about.
Does any body else know what he was talking about? I wonder if a similar thing is happening with people swimming in a marina, since marinas tend to pack some serious amperage.

The water pump for our house is a submersible 220v pump. There is nothing wrong with using one as long as it is set up properly. It is easier since you dont have to winterize the pump, just blow out the lines in the house at the end of the season. Submersible (below) and jet pumps (above) are the 2 options used.

Ours is within 20 feet of our swim raft. To date, nobody has been fried....

[jrc]

Birchhaven, knowing what I do about electricity, there is no way you could get enough energy from this type of electric field to hurt anybody. The frequency and power levels are way to low to couple anything.

Now a submersable pump is theoretically prone to physical damage to the motor or wire insulation that could couple power directly to the water. An onshore pump is less vulnerable.

Theres lots about electcuting swimmers on the internet. I read that salt water is safer than fresh. If a bare hot conductor is in the water, some of the current will travel through the water to ground, as it's the easiest path. Since salt water is more conductive than humans, the current stays in the water and out of your body. Since lake water is less conductive, you become the path of least resistance.

[AkwaMarina]

https://cc.readytalk.com/cc/playback...k.do?id=5h5qwc

Eaton Marine did some great webinares on this. I hope the link works, it should be free to view for ~30 days

[Bear Islander]

I am a New Hampshire licensed Master Electrician. GFCI protection is only required on NEW construction. If you have an old electrical system and you just keep fixing it and using it there is no requirement that you add GFCI protection.

As has been mentioned the only way to have full protection is to put a large GFCI on the feed from shore. This would be VERY expensive and not required by the National Electric Code. Also this GFCI would be subject to a lot of nuisance tripping. After the the power went out a few times people would be screaming to eliminate the expensive GFCI that is not required by code.

I would never run 120 volt or 240 volt power to my dock and it is not smart to swim around voltages like that. Low voltage lighting is available and is cheap, safe and easy to install. Other than low voltage the only good answer is stay away from electricity when in the water.

[birchhaven]

Originally Posted by AkwaMarina

https://cc.readytalk.com/cc/playback...k.do?id=5h5qwc

Eaton Marine did some great webinares on this. I hope the link works, it should be free to view for ~30 days

This video explained this incredible well. I now know more than I ever wanted to know about this.

But it got my wheels turning, could a person install an underwater ground rod in the lake bottom (say 6 feet from lake bottom, in 10 feet of water under the dock), so if your boat has leakage, the ground rod will complete the circuit before a unsuspecting swimmer does?

[mas1992bc]

I'm not an electrician, so I apologize if this is a dumb question, but I have a related question. What about swimming near a circulator (like the ones used to circulate water around your dock in the winter)? Those are plugged into shore power, with the cord running directly into the water. Obviously, nobody is swimming in the winter, but would it be unsafe to swim in the water with one of those plugged in (if, for some reason, you still had it plugged into power in the spring)?

[Belmont Resident]

Originally Posted by mas1992bc

I'm not an electrician, so I apologize if this is a dumb question, but I have a related question. What about swimming near a circulator (like the ones used to circulate water around your dock in the winter)? Those are plugged into shore power, with the cord running directly into the water. Obviously, nobody is swimming in the winter, but would it be unsafe to swim in the water with one of those plugged in (if, for some reason, you still had it plugged into power in the spring)?

I think those come out long before exposed skin goes in.
But you are correct if they were not properly ground faulted then there may be a problem.
My .02, anyone who knowingly has electricity out to their dock without proper ground fault weather it is legal because it's been there since before time or not is asking for trouble. Just curious if something did happen and a loved one or family member got hurt or worse it would still have been legal but that person would still have gotten hurt because of something you could have prevented.
2 years ago I had a truck catch on fire because the block heater wasn't plugged into a ground fault outlet. Well the garage had none in it to begin with.
The cord had broken from use and shorted on the bumper catching the grill on fire while sitting right in front of my garage. I've since changed over to arch protection outlets, costly but worth it since I'm sometimes caught working out in the rain or have things plugged in during the winter.

[kjkam]

Alot of people don't know that you can get stray voltage from the ground leg, this could be caused by improper wiring in the house or even a faulty transformer. We had this issue with our boat lifts, the soltution was to electrically insulate the motor (which the frame is grounded) from the rest of the metal on the boat lift, the utility also changed the transformer to our house. which brought it down. We could only measure about 5VAC, but that was enough to give you a tingle if you were in the water and touched the boat lift that was above the water.

[Bear Islander]

Here is another thing to think about. Every now and then the lake gets real high in the spring. The docks at my marina have been underwater during those years. Under those conditions you must walk through the water to get to your boat. Therefore it is essential that ALL power to the docks be shut down when the water gets to, or above, dock height.

[Lakegeezer]

After reading all the posts, I'm a bit confused. If there is a GFI back at the breaker, and it is tested often, is there any problem with electric power at the dock or in the water? My assumption is/was that a GFI makes it all OK - and can't believe that anyone would have dockside power unprotected this way. Or, are there situations where the GFI doesn't provide the protection required?

[kjkam]

When I was doing my research to find the issue, there are two ways to get electricity into the water. The first is through some type of faulty wiring or installation, a dead short to the water, which would be prevented by the GFI or breaker. The second is where there are stray voltages caused by inbalanced electrical grids, faulty transformers, ect, basically caused by anything before your meter. These stray voltages are not very high and are not just found in the water, but in rare cases they can be enough to cause injury or death. The electrical grid in this country is in pretty good shape, so cases are rare.

[XJLPS]

I was taking in an ice eater one spring in water up to my neck ,when i approached the eater I notice 3-4 salmon dead next to it , I thought maybe they got hit by the prop. Boy was I wrong I grabbed that thing and got a jolt from the unit . After killing the power we brought it on shore turned it on and put a voltmeter on it it was putting out 220 volts on the frame . Turns out it was hooked up by a guy who claims to be an electrician . I wouldnt let him change a bulb in my kids easybake oven .