Here are some items that Marinas should look into that are alarms etc. that alert of electric in the water.
* http://www.safewatersystemsinc.com/ "Life-threatening electricity can enter the water of pools, spas, marinas or around a dock from many different sources without anybody knowing that it’s there… a lurking invisible and silent killer. Our Shock-Guard™ 24/7 system prevents loss of life from electrocution or electric shock drowning by monitoring the water 24/7 and sounding an alarm, even when a small amount of electricity is detected. Shock-Guard™ 24/7 also instantly trips a GFI circuit, shutting down the power to the pool system. The system also protects boats from marine corrosion, especially in salt water marinas and docks. Shock-Guard™ 24/7 provides a much safer swimming and boating environment and “Peace of Mind” for everyone! "
* http://www.docklifeguard.org/ Detects Electricity on your Dock and in the water around your Dock
•Visual and Audible Warning of Electricity detection in the water or on your dock.
•Weather resistant enclosure
•Super bright LED indicator
•Detects hazardous electrical voltage in water or on dock
•Radius of Detection; approximately 40'. Water conditions and underwater objects may reduce range
•Should not be used as substitute for correct dock wiring
•Detects if dock is electrified or water is electrified
•Professional installation available
https://youtu.be/Qc6hqCXMKfQ
Might be good for houseboaters and cruisers as well that have onboard electric.
Now for the details of ESD
https://youtu.be/lRL6kFNbRpU
3 Children Rescued from Pool with Electrified Water
This video depicts the frightening occurrence when electric voltage is introduced into water. If you prefer not to watch, here is the timeline of the video:
0:06 – Child 1 is electrocuted
0:13 – The father’s heroic response rescues his daughter (not advised)
0:15 – Another child is still in the pool
0:27 – Another man heroically rescues his granddaughter (not advised)
http://www.boatus.com/seaworthy/magazin ... lained.asp
ESD Explained
By Beth Leonard
What every boater needs to know about Electric Shock Drowning.
Red exclamation point
Download the PDF version of this article.Photo of a girl jumping into a lake for a swimPhoto: Brian Fitgerald
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One year ago, over Fourth of July weekend, Alexandra Anderson, 13, and her brother Brayden Anderson, 8, were swimming near a private dock in the Lake of the Ozarks in Missouri when they started to scream. Their parents went to their aid, but by the time the siblings were pulled from the lake, they were unresponsive. Both children were pronounced dead after being transported to a nearby hospital. About two hours later, Noah Winstead, a 10-year-old boy, died in a similar manner at Cherokee Lake, near Knoxville, Tennessee, and Noah's friend, 11-year-old Nate Parker Lynam, was pulled from the water and resuscitated but died early the following evening. According to local press reports, seven other swimmers were injured near where Noah died. These were not drowning victims. In all of these cases, 120-volt AC (alternating current) leakage from nearby boats or docks electrocuted or incapacitated swimmers in fresh water.
This little-known and often-unidentified killer is called Electric Shock Drowning, or ESD, and these deaths and injuries were entirely preventable. In just four months last summer, there were seven confirmed ESD deaths and at least that many near misses; in all likelihood, dozens more incidents went undetected. Every boater and every adult who swims in a freshwater lake needs to understand how it happens, how to stop it from happening, and what to do — and not to do — if they ever have to help an ESD victim.
Fresh Water + Alternating Current = Danger
Kevin Ritz lost his son Lucas to ESD in 1999, and he shared his story with Seaworthy in "A Preventable Dockside Tragedy" in October of 2009. Since his son's death, Ritz has become a tireless investigator, educator, and campaigner dedicated to preventing similar tragedies. "ESD happens in fresh water where minute amounts of alternating current are present," Ritz said.
What does "minute" mean exactly? Lethal amounts are measured in milliamps, or thousandths of an amp. When flowing directly through the human body, these tiny amounts of current interfere with the even smaller electrical potentials used by our nerves and muscles. Captain David Rifkin and James Shafer conducted extensive testing of all aspects of ESD for a Coast Guard study in 2008, including exposing themselves to low-level currents in fresh water. "Anything above 3 milliamps (mA) can be very painful," Rifkin said. "If you had even 6 mA going through your body, you would be in agonizing pain." Less than a third of the electricity used to light a 40-watt light bulb — 100 mA — passing directly through the heart is almost always fatal.
Current Level Probable Effect On Human Body
1 mA Perception level. Slight tingling sensation. Still dangerous under certain conditions.
5 mA Slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary reactions to shocks in this range may lead to injuries.
6-16 mA Painful shock, begin to lose muscular control. Commonly referred to as the freezing current or let-go range.
17-99 mA Extreme pain, respiratory arrest, severe muscular contractions. Individual cannot let go of an electrified object. Death is possible.
100-2,000 mA Ventricular fibrillation (uneven, uncoordinated pumping of heart). Muscular contraction and nerve damage begin to occur. Death is likely.
2,000+ mA Cardiac arrest, internal organ damage, and severe burns. Death is probable.
Source: OSHA
Why fresh water and not salt? Salt-water is anywhere from 50 to 1,000 times more conductive than fresh water. The conductivity of the human body when wet lies between the two, but is much closer to saltwater than fresh. In saltwater, the human body only slows electricity down, so most of it will go around a swimmer on its way back to ground unless the swimmer grabs hold of something — like a propeller or a swim ladder — that's electrified. In fresh water, the current gets "stuck" trying to return to its source and generates voltage gradients that will take a shortcut through the human body. A voltage gradient of just 2 volts AC per foot in fresh water can deliver sufficient current to kill a swimmer who bridges it. Many areas on watersheds and rivers may be salty, brackish, or fresh depending upon rainfall or tidal movements. If you boat in these areas, treat the water as if it were fresh just to be on the safe side.
Why alternating current and not direct current (DC)? The cycling nature of alternating current disrupts the tiny electrical signals used by our nerves and muscles far more than the straight flow of electrons in direct current. "It would require about 6 to 8 volts DC per foot to be dangerous," Rifkin said, or three to four times as much voltage gradient as with AC. "Regardless of the type of voltage, the larger the voltage, the larger the gradient over the same distance." There have been no recorded ESD fatalities from 12-volt DC even in fresh water because there is less chance of the higher voltage gradient necessary developing with DC's lower voltages.
Illustration of how electricity gets in the waterFor stray AC to get into the water, there must be an electrical fault and a fault in the safety ground. (Courtesy David Rifkin)
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How does that electricity get into the water in the first place? In a properly functioning electrical system, all of the 120-volt AC current that goes into the boat through the shore power cord returns to its source — the transformer ashore or on the dock where it originated. For any of that current to wind up in the water, three things have to occur.
Electrical fault. Somewhere current must be escaping from the system and trying to find another path back to its source ashore.
AC safety ground fault. The AC grounding system must be compromised so that stray current cannot easily return to ground through the ground safety wire. Any stray electricity then has only one path back to its source — through the water.
No ground fault protection. Any current returning to its source through the water will create a slight but detectable difference between the amount of current traveling to the boat and returning from it through the shore power cables. Ground Fault Protection (GFP) devices, like Ground Fault Circuit Interrupters (GFCIs) required in bathrooms ashore, are designed to detect differences measured in milliamps and to shut down the electricity within a fraction of a second. If the circuit does not have one, then electricity will continue to flow into the water.
If all of these conditions exist, then some or all of the boat's underwater metals, such as the propeller, stern drive, or through-hull fittings, will be energized, and electricity will radiate out from these fittings into the water. If the boat is in saltwater, the current will dissipate without doing damage unless a diver grabs hold of the energized metal. In fresh water, 120-volt AC will set up a dangerous voltage gradient that will pass through any swimmer who bridges it.
Finding Out If Your Boat Is Leaking Current
Photo of an inexpensive circuit testerAn inexpensive circuit tester.
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Figuring out if your boat has a problem requires two specialized tools — a basic circuit tester and a clamp meter — that together cost about $150. If you keep your boat in a freshwater marina, the marina operator should have both and be using them to check the boats on their docks.
To determine if your boat is leaking AC, start by checking the dock wiring. Plug the circuit tester into the shore power cord receptacle you use on your pedestal. The lights on the circuit tester will tell you whether or not the shore power system is functioning as it should. There are situations where those lights can mislead you, but as a first approximation, assume all is well if the circuit tester says it is. If you find any problems, alert your marina manager or call an electrician certified to ABYC (American Boat and Yacht Council) standards.
Once you have established that the dock's electrical system is sound, take the clamp meter and put it around your shore power cord. Most electricians use a clamp meter to measure the current flowing through the neutral, hot, and ground wires separately, but we are interested in whether or not all of the current entering the boat is leaving it. If that is the case, the current passing through all of the wires will sum to zero, and that's what the meter will show when the clamp is put around the entire shore power cord. If the clamp meter shows anything but zero, either some of the current going to your boat is entering the water, or current leaking from the dock or another boat is returning to its source ashore through the metal fittings on your boat. To determine which, turn off the power at the pedestal. If the clamp meter continues to show the same reading it did when the pedestal was on, the current is coming from somewhere else. If any or all of the current goes away, then your boat is leaking some current into the water.
Photo of a clamp meterThis clamp meter shows a 7-amp difference between the current going into the boat and coming out. (Courtesy David Rifkin)
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Unfortunately, that's not quite all there is to it. Many of the most dangerous AC loads on a boat, like air conditioning and refrigeration, are cycling loads. A fault in one of these will only show up if that equipment is running when you clamp the cord. To be sure your boat is not leaking AC into the water, you must run all your AC loads while clamping the cord and look for any reading but zero. If you find a problem, unplug your boat and don't plug it in again until you get an electrician trained to ABYC standards to figure out what is wrong and fix it.
Eliminating Current Leakage
That your boat is not leaking AC into the water right now is no guarantee that it never will. Electrical faults and ground faults develop in the marine environment all the time. There are two ways to eliminate the risk altogether.
The first — and best — alternative is to completely isolate the AC shore power system from the AC system on the boat. Then any stray AC on the boat will return to its source on the boat and will not enter the water. An isolation transformer transfers electricity from the shore to the boat and back again using the magnetic field generated by the electrical current rather than through shore wires physically touching the boat's wires. If you want to be absolutely certain your boat cannot leak alternating current into the water, install an isolation transformer.
The second alternative is to install ground fault protection in the boat's and the dock's AC system that will shut off the current if the amount of electricity going out differs by a certain amount from that returning. "The European, Australian and New Zealand standards require ground fault protection on a marina's main feeders and power pedestals," Rifkin said. "They've had zero ESD fatalities in the nearly 30 years they've had this in place." In the U.S., NFPA (National Fire Protection Association) 303 (Fire Protection Standard for Marinas and Boatyards) requires GFP devices that trip at 100 mA or lower on all docks. But these devices can be expensive to retrofit and maintain in a large marina, need to be tested monthly to keep them working properly, and are subject to nuisance trips in the marine environment, so the requirements have not been adopted or enforced uniformly at the local level.
The ABYC made ground fault protection on boats part of the E-11 electrical standard this year. Equipment Leakage Circuit Interrupters (ELCIs) that trip at 30 mA are to be installed on all new vessels built to ABYC standards, but very few older boats are equipped with them. Companies like North Shore Safety have started to offer easy to retrofit ELCIs and UL-approved cords with integrated ELCIs — these run from $200 to $400. Home building suppliers like Lowe's sell 15-amp pigtails equipped with GFCIs for around $30. Either of these could be used with a shore power cord from a house to a private dock to charge a boat's batteries.
Since his son died 14 years ago, Kevin Ritz has comforted dozens of families who have lost children as he has, and he has encouraged them to join forces with him to educate others. His goal is to put himself out of business. If each and every boater takes responsibility for his or her boat, Ritz could get his wish.
https://www.mikeholt.com/mojonewsarchiv ... 031024.htm
Stray Voltage/Current at Marina
I really appreciated your newsletter on stray voltage. I am dealing with this very problem and throwing the last two years of my life into research as to how to avoid it at marinas. I have stockpiled enough equipment to test anything. I can offer solutions to some marina tenants, but the waters will always be hot in my opinion.
Two years ago, my company was asked to handle an insurance claim at a local marina. A wire had come loose during a tide change and lay just feet from a sailboat. The boat had a steel keel and no protection. The owner asked what I thought. I told him that the sailboat should have come with protection from the factory, especially since it was a $250,000 vessel. I then called the manufacturer. They claimed that protection units were too costly and so did not install them on their vessels - even the $250,000 ones! The marina owner paid the claim for the damage to the customer's yacht and then the customer approached me, asking for help. He wanted a protection unit. I told him they were around $1,000 but that seemed too much money for him. Then, he requested a galvanic isolator. That unit is only around $100 and offers protection to a meager 1.4 volts.
Shortly after that, the local divers called me and stated that the zincs were foaming off of some of the boats at that same marina like Alka-Seltzer tablets. I immediately dropped what I was doing and went to investigate. There were 32 amps on the marina ground lead. I called the owner of the marina and he simply could not believe me. I was a new technician in town that was making waves.
He called the contractor that had performed a large amount of work at the marina the year before. The contractor had been in business for over 30 years and had a rather large operation with several employees and quite a fleet. When he arrived at the marina, the owner immediately voiced his complaints against me. The electrician asked his employee to test the ground lead at the end of the marina. When the employee opened the power box at the marina's end, the ground was unhooked. Wanting to attach the ground lead to the respective terminal so that the Fluke clamp-meter could be used, when the wire touched the terminal post, sparks flew from the wire, scaring the employee, marina owner, and electrician. The electrician insisted that his employee attach the wire with sparks flying and then clamp it with the Fluke. There were 32 amps on the ground lead. The electrician was horrified to say the least. I do not know if anyone reading this knows what 32 amps on the ground lead at a saltwater marina means, but I know that every professional reading this only has to think for a split second to come up with several scenarios.
The marina owner agreed to have a substantial sum of money spent on the marina's electrical wiring. But still, no one really got the point. While everyone was still present, I unplugged one boat and the amperage on ground dropped by 12 amps! The boat owners were present on the vessel. They claimed that their friend made their shore cord. I traced every boat causing the problem and serviced the wiring. One tenant had the hot and ground reversed on his space heaters.
I was asked to test another marina with over 500 slips and give my analysis of the marina. What I found was astounding. Forty percent of the vessels tested were miswired. The test was bogus as many of the tenants were not present and things can change with the power turned off or unplugged. So, the number could have been even bigger.
I own a magnetic field strength tester, which is very handy in testing if appliances such as water heaters or battery chargers are working before climbing down into the bilge to look. I took it to a large metal culvert that was between the marina and a substation only six blocks away. My meter was off the scale. The culvert is in the bay water and in the soil. I knew where the lost energy was going - back to the substation! Millions of dollars worth a year, costing boat owners millions more in premature zinc loss, pitted and damaged prop shafts, props, trim tabs, thru hull fittings and paint. Just to name a few items I have seen. Rudderposts are another.
If anyone needs help, please feel free to contact me or visit our Website at http://www.garnermarine.com.
Dave Garner
Garner Services
1(360) 956-1190
http://www.ajc.com/news/national/what-e ... 4EcvjiUMO/
What every parent needs to know about electric shock drowning
Debbie Lord
- Cox Media Group National Content Desk
Updated12:38 p.m Friday, April 22, 2016 Filed in National/World News
Sean Gallup
(Photo by Sean Gallup/Getty Images)
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Two Alabama teens jumped from a boat dock into a fresh water lake to take a swim after a day of picnicking and enjoying the warming spring weather. But sadly, one of them never made it home.
The body of one of the girls, Carmen Johnson, 15, of Hartselle, didn’t resurface. Her body was recovered an hour later, having drowned in the fresh waters of Smith Lake in Winston County, Ala.
While authorities have not said for sure what caused Carmen’s death, they believe the Priceville High School cheerleader may have drowned after she was electrocuted by a 120-volt alternating current that was “leaking” into the water.
Carman’s death last week highlights a little-known but growing danger that comes with swimming near docks and the boats secured to them. And it sounds like every parent's nightmare.
The incidents of Electric Shock Drowning – or drowning that happens as a result of an electric shock – have been on the rise as boats and docks are being stocked with more electric appliances and devices. If not properly installed or maintained, the devices can “leak” electric current into the water, setting up the potential for tragedy.
As the weather gets warmer and more people head outdoors for a fun time on the water, here’s a primer on ESD and some steps to take to keep safe this summer.
What is an Electric Shock Drowning (ESD)?
ESD happens when a swimmer comes into contact with electrical current. The current – in this case, alternating current (AC) – causes skeletal muscular paralysis, lasting for only an instant, but long enough to incapacitate a swimmer allowing him to drown.
Where does the electricity come from?
The electric current “leaks” from boats and docks into the water. It can come from frayed wires, improperly wired systems or an AC grounding system that is damaged or malfunctioning.
What causes people to be electrocuted?
Electrical current will always attempt to return to its source in order to complete the elecrical circuit. Electrical current is resourceful and will find any way to do that, taking the path of least resistance and most conductivity (anything that will help the current move along its path). The way alternating current (AC) searches for its source is the most deadly for humans because it takes only a small amount of AC to disrupt the electrical impulses that control our muscles and nerves.
Why does ESD happen in fresh water and not salt water?
We go back to conductivity for the answer. Fresh water is not a good electrical conductor. Because it is not a good conductor, the alternating current looks for something better. A human body in fresh water becomes that something better. The high amount of salt in humans make our bodies far better conductors of electrical current than fresh water.
How much electricity is needed for this to happen?
Not much at all. It takes only small amounts of leaking AC to incapacitate or electrocute a person. As small an amount as 15 milliamps can cause paralysis, 100 milliamps – or a third of the amount of electricity need to light a 40-watt light bulb – can kill a person in seconds. In comparison, a double AA battery produces 2400 milliamps per hour.
Doesn’t anyone regulate docks and boats secured to them?
There are marine codes that regulate docks and boats. They are NFPA 303 (Fire Protection Standard for Marinas and Boatyards), NFPA 70, and National Electric Code 555 (NEC). Boatus.com also notes that “boats not wired in accordance with standards set forth by the American Boat & Yacht Council (ABYC) can be a source of AC leakage.”
Can you tell if water is unsafe to swim in?
No, but here are some tips that could keep you safe.
•Never swim within 100 yards of any fresh water marina or boatyard.
• If you have a boat, have it tested to make sure it is not leaking electricity. You can buy a clamp meter and test it yourself.
•Have a qualifed electrician do any electric work needed on a dock or on your boat.
•Do not use a household extension cords for powering your docked boat.
If you feel "tingly" in the water, you could be at risk for shock. In that case you should: (courtesy of boatus.com)
•Have someone turn off the shore power connection at the meter base and/or unplug shore power cords.
•Tell anyone in the water to move away from the dock.
•Stop anyone else from entering the water.
•If you believe someone has been shocked, reach, throw, row, but don’t go into the water to get to anyone who you think has been shocked.
• Call for help. Use 911 or VHF Channel 16.
•Try CPR on the person; don't stop until trained help arrives.
Sources: boatus.com; acegroup.com; Boating Magazine; Decatur Daily News
