Electric Shock Drowning detection?
- Thread starter skyhawk
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Comodave
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The new GFI type devices on docks will mitigate the problem very well. I don’t know of any detectors, but there may be something out there. In saltwater it isn’t nearly as likely as in freshwater.
psneeld
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Some unplug the vessel they are working on, sometimes other boats around also. In salt water because of the almost impossibility, I haven't seen any unplug where I am....then again I may just have missed them doing it.
Not the water, but they can test the boat's shore power cords....
Read some info from this link...
https://gilwellbear.wordpress.com/2015/05/18/ac-safety-tests-for-boats/
LenBuchanan
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There are detectors out there. I saw this one advertised in either Lats & Atts magazine or Lakeland Boating:
https://shockalarm.com/
Price varies from around $59 to $99
https://shockalarm.com/
Price varies from around $59 to $99
Item that disturbs me re elect-shock-current in fresh water; at or around a dock:
What if the area tested void of electricity at first... but, then after you're in the water for some reason electricity suddenly enters the water in that area.
I don't go into fresh water at or near docks.
What if the area tested void of electricity at first... but, then after you're in the water for some reason electricity suddenly enters the water in that area.
I don't go into fresh water at or near docks.
psneeld
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My understanding about ESD is that a person can be next to you and not notice a thing but the current can be passing through you.
So I am a bit skeptical of the reference alarm.
But I cant really say one way or the other.... so I would like to see an experts review of it or similar tech.
So I am a bit skeptical of the reference alarm.
But I cant really say one way or the other.... so I would like to see an experts review of it or similar tech.
From peoples personal stories and news reports I've read, where some died due to electric-shock drowning... it seems the intensity of electric current dissipates the further you get from the "bleed" of electric current into water.
If close enough to the electric-bleed it can paralyze you so you can't swim; and, then drown. From what I recall reading - if a person is paralyzed in the freshwater by electricity and another person jumps in beside them the rescuer will also be affected.
Another item I've read regarding electric-current in freshwater comes from a boat itself. Not clear how that all fits into the mix of electric-shock drowning.
In my case - the bottom line is: I don't swim in the freshwater at the freshwater location we dock our boat.
Seems there are few and far between deaths form this electric danger - I just don't want to be one!
Bottom line for me: Don't swim around electrified docks in freshwater!
Is anyone familiar with what causes the electrical leak or how it happens in most cases. I assume it is coming from the dock wiring, but is it chafed insulation, faulty box connections, corrosion, or all of the above. I haven't heard of a problem with swimming around a boat with the generator running at anchor in fresh or salt water. I do it all the time with mine in salt water, especially when cleaning the bottom while using an oilless compressor. Maybe I shouldn't be.
psneeld
Guru
From peoples personal stories and news reports I've read, where some died due to electric-shock drowning... it seems the intensity of electric current dissipates the further you get from the "bleed" of electric current into water.
If close enough to the electric-bleed it can paralyze you so you can't swim; and, then drown. From what I recall reading - if a person is paralyzed in the freshwater by electricity and another person jumps in beside them the rescuer will also be affected.
Another item I've read regarding electric-current in freshwater comes from a boat itself. Not clear how that all fits into the mix of electric-shock drowning.
In my case - the bottom line is: I don't swim in the freshwater at the freshwater location we dock our boat.
Seems there are few and far between deaths form this electric danger - I just don't want to be one!
Bottom line for me: Don't swim around electrified docks in freshwater!
All I know is the electricity is seeking ground...yes electricity with take as may paths to ground as it can.... but I think in the case of ESD, it is not clear exactly what might happen in every case.
As I said, I would like to see a pretty decent review of someone well versed in ESD on the technology.
From what I understand saltwater posed little to no problem regarding electric shock.
Wish a pro would weigh in on this!
rslifkin
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My understanding of the salt vs fresh water thing is that a human is less conductive than the surrounding salt water, but more conductive than fresh water. So in salt water, very little current will go through your body in most cases, even with stray current present. In fresh water, if you end up in the wrong spot relative to the current flow, you become a (relatively) good conductor and get fried.
ESD website:
https://www.electricshockdrowning.org/
Diagrams:
https://www.electricshockdrowning.org/esd--faq.html
https://www.electricshockdrowning.org/
Diagrams:
https://www.electricshockdrowning.org/esd--faq.html
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SteveK
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Nigel Calder describes a method where you take a volt meter and insert the positive lead into the dock pedestal neutral leg and put the negative lead in the water. It should be zero, and anything but a very low voltage (way less than 1 volt if I remember correctly) is considered dangerous. Next time I get out his book, I'll get the exact numbers.
tiltrider1
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Lot of questions here.
First, this is a fresh water problem. In salt water the boat suffers all the damage and anyone swimming in the neighborhood won't notice anything.
Second, the problem is caused when the boat has a faulty ground wire and a power wire suffers a failure. The problem is usually blamed on faulty grounds because the ground is the safety net in case there is a failure in the power/neutral connection.
Third, if you were to swim towards a boat that was leaking power, you would start to get a tingling feeling, if you tried to continue swimming towards the boat you would have difficulty controlling your motor functions. Most likely the tingling feeling would scare you away. Now if current was drawing you towards the boat you have a problem.
Fourth, with a diver there are too many variables but the fresh water drowning victims rarely if ever have water in their lungs. In other words they didn't drown. Their motor functions became impaired and they died from lack of oxygen. I know dead is dead but it is important to note that a regulator would not help.
In most cases fresh water drowning victims jumped in the water next to the boat. However, thousands of case have been wrongly diagnosed as drowning because no one understood what really happened. The Coroner would see all the signs of oxygen starvation and noted that the victim was found in the water, victim drowned. Now there are hundreds of suspect cases form years ago were we now question if fresh water electro shock might be the cause. One such case evolved a woman hanging on to the back of the boat while here husbanded plugged the boat in using an old extension cord. One moment she was talking to him the next he found here dead, was labeled as a drowning but there seems to be evidence that she stopped talking when the boat got plugged in.
Back to the diver. If the diver jumps in at the wrong spot he could be in trouble. If he climbs down a ladder he will notice the current first and climb out.
First, this is a fresh water problem. In salt water the boat suffers all the damage and anyone swimming in the neighborhood won't notice anything.
Second, the problem is caused when the boat has a faulty ground wire and a power wire suffers a failure. The problem is usually blamed on faulty grounds because the ground is the safety net in case there is a failure in the power/neutral connection.
Third, if you were to swim towards a boat that was leaking power, you would start to get a tingling feeling, if you tried to continue swimming towards the boat you would have difficulty controlling your motor functions. Most likely the tingling feeling would scare you away. Now if current was drawing you towards the boat you have a problem.
Fourth, with a diver there are too many variables but the fresh water drowning victims rarely if ever have water in their lungs. In other words they didn't drown. Their motor functions became impaired and they died from lack of oxygen. I know dead is dead but it is important to note that a regulator would not help.
In most cases fresh water drowning victims jumped in the water next to the boat. However, thousands of case have been wrongly diagnosed as drowning because no one understood what really happened. The Coroner would see all the signs of oxygen starvation and noted that the victim was found in the water, victim drowned. Now there are hundreds of suspect cases form years ago were we now question if fresh water electro shock might be the cause. One such case evolved a woman hanging on to the back of the boat while here husbanded plugged the boat in using an old extension cord. One moment she was talking to him the next he found here dead, was labeled as a drowning but there seems to be evidence that she stopped talking when the boat got plugged in.
Back to the diver. If the diver jumps in at the wrong spot he could be in trouble. If he climbs down a ladder he will notice the current first and climb out.
fgarriso
Guru
From the web site;
ShockAlarm is a floating, monitoring alarm that protects your family, friends, and pets from Electrical Shock Drowning. It detects stray electrical currents that are potentially dangerous. This is a passive device which means it isn’t connected to an electrical system that could pose added dangers when around water. Once activated, the ShockAlarm will monitor for electric current constantly.
??? Do you die from the Electrical Shock or Drowning ???
"electrical currents that are potentially dangerous" ??? which currents are dangerous ???
rgano
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When I first read a thorough article on electric shock drowning it was by a gentleman who was both familiar with boat electical systems and who had tragically lost a child to ESD. He later took his VOM (with no special attachments) and actually tested the water where he had lost his child and found voltage which, as I remember, was taced to a bare 120-volt wire resting on an engine or some such item in the boat behind which his child died. This man, through his education efforts, is responsible for a lot of the awareness we have of this problem.
Iggy
Guru
Yes, in salt it will take the path of lest resistance. SO some may go straight into the seabed and not all into the person. NOT only can it come from the dock but it could come from a boat that is wired incorrectly in some way. Or maybe there galvanic isolator is not working.
AZ2Loop
Senior Member
skyhawk, there is another one called Shock Alert that was developed somewhere near Lake of the Ozarks as I recall. LOTO is a huge freshwater lake that has a tremendous amount of development all around it. So many docks and so many boats, and around 1200 miles of shoreline. Electric shock drownings are a topic of interest there for sure. Thankfully the cases are very few and far between, but obviously tragic when they do take place. As a poster above indicated, the problems can be from a dock, or from a boat as I understand it. Again, thankfully rare.
One point to make. If one is swimming near a dock and feels any kind of electrical tingle, the tendency is to swim to the dock and grab the ladder. That has been fatal at times. One should swim AWAY from the dock and call for help to be picked up from the water away from the dock. That's not always possible, and I'm sure each case does not come with such warning.
One point to make. If one is swimming near a dock and feels any kind of electrical tingle, the tendency is to swim to the dock and grab the ladder. That has been fatal at times. One should swim AWAY from the dock and call for help to be picked up from the water away from the dock. That's not always possible, and I'm sure each case does not come with such warning.
sunchaser
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North of Phoenix is located Lake Pleasant. Last year, at a nice marina, a slipped boat was going through some owner electrical work. For some reason a person on the vessel went into the water and became distressed. Another person went in the water to save them. Both died from electric shock.
The local press had some decent write ups as to fresh water induced electric shock. In this case the marina came out ok following testing at each slip. But the boat owner was monkeying around electrically with incoming power as if his boat was a house on dry land.
The local press had some decent write ups as to fresh water induced electric shock. In this case the marina came out ok following testing at each slip. But the boat owner was monkeying around electrically with incoming power as if his boat was a house on dry land.
rgano
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I suppose the idea of shutting down all AC generation before swimming in FW must include attention to that silent machine which could be overlooked, the inverter.
I once had a diver show up at my boat in Georgia. He had a big pair of binoculars around his neck over his wetsuit. I asked him why.
"To look for Gators"
After scanning the shore, he got in the water and went to work. I soon heard thunder. He popped up and I asked him if he should get out of the water.
"Naw. I just get a little tingle when the lightening hits."
I have no idea if he's still alive.
"To look for Gators"
After scanning the shore, he got in the water and went to work. I soon heard thunder. He popped up and I asked him if he should get out of the water.
"Naw. I just get a little tingle when the lightening hits."
I have no idea if he's still alive.
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Esd
This is an important and potentially deadly topic so I am going to go through the posts to date and comment and/or clarify them. I am an active marine electrician and when ABYC was doing in person certification classes, I was an instructor. For those that made erroneous posts, I apologize for pointing the errors out but this is too important a topic to allow an error to stand.
Post #2: Excellent reference. Jim also has several other posts regarding the subject on his site.
Post #3: There are detectors but none of us "in the business" endorse there use for exactly the reason that was pointed out in Post #4; all is well until a defective circuit is energized.
Posts #5 & 6: Electricity in the water from a point source is a 1/r^2 field. That is if the victim is r feet from the point source, doubling that distance will decrease the field by a factor of 4.
Post #8: The answer is that the fault is on the boat.
Post #9: Not entirely correct; electrical current is attempting to return to its source and will take all paths to return there. It is not really "seeking ground". This is a popular misconception.
Post #10: True. There have been no documented cases of ESD in salt water. That said though, be mindful that in estuarial waters, significant rain can create a layer of relatively fresh water that floats on top of the underlying salt or brackish water and could cause an ESD hazard.
Post #11: The concept is correct but with the caveat that the human body is basically a sack of saline solution with some bones and other stuff. We are just about as saline as sea water.
Post #12: Great references.
Post #13: The lodestone for understanding ESD. Kevin Ritz is a very good friend and he is the father that tragically lost his son and refused to accept the coroner's report that it was death by drowning. Lucas was wearing a PFD when he died-his head never went below the water! We are aware of ESD because of Kevin's expertise and tenacity.
Post #14: I am not aware of this test. Please follow-up.
Post #15:
First point: True with the caveat discussed in my comment on Post #10.
Second point: Absolutely correct. It takes to faults to create ESD.
Third point: That is really a function of how strong the electrical field is and how sensitive the victim is to electric effects.
Fourth Point: Correct.
Post #16: See my comment on Post #3. I am not a doctor but "drowning" occurs when water enters our lungs. Electric Shock Drowning is a term that was coined to describe the physiological response to someone entering an electrical field and:
Post #18: The current is not going to the seabed it is using the water column to return to its source e.g.; the N>G bond at the transformer secondary on the dock.
A galvanic isolator blocks cathodic protection current and passes AC that is present on the safety ground (green) wire.
Post #19: I think we loose about 10 to 15 people to ESD each year.
Caution against swimming towards a ladder is spot on.
Post #20: A sad and recurring story.
Post #21: Correct.
Post #22: Not really. The prohibition is to not swim in a fresh water marina that has electrical service. That said, you are spot on regarding the inverter or inverter/charger.
Post #23: Probably the best in depth discussion that I have seen and written at a level that is understandable.
Post #24: No comment.
Again, I created this post to try and get all of the participants on the same page...not to embarrass anybody. Please take my comments in the spirt in which they were made.
This is an important and potentially deadly topic so I am going to go through the posts to date and comment and/or clarify them. I am an active marine electrician and when ABYC was doing in person certification classes, I was an instructor. For those that made erroneous posts, I apologize for pointing the errors out but this is too important a topic to allow an error to stand.
Post #2: Excellent reference. Jim also has several other posts regarding the subject on his site.
Post #3: There are detectors but none of us "in the business" endorse there use for exactly the reason that was pointed out in Post #4; all is well until a defective circuit is energized.
Posts #5 & 6: Electricity in the water from a point source is a 1/r^2 field. That is if the victim is r feet from the point source, doubling that distance will decrease the field by a factor of 4.
Post #8: The answer is that the fault is on the boat.
Post #9: Not entirely correct; electrical current is attempting to return to its source and will take all paths to return there. It is not really "seeking ground". This is a popular misconception.
Post #10: True. There have been no documented cases of ESD in salt water. That said though, be mindful that in estuarial waters, significant rain can create a layer of relatively fresh water that floats on top of the underlying salt or brackish water and could cause an ESD hazard.
Post #11: The concept is correct but with the caveat that the human body is basically a sack of saline solution with some bones and other stuff. We are just about as saline as sea water.
Post #12: Great references.
Post #13: The lodestone for understanding ESD. Kevin Ritz is a very good friend and he is the father that tragically lost his son and refused to accept the coroner's report that it was death by drowning. Lucas was wearing a PFD when he died-his head never went below the water! We are aware of ESD because of Kevin's expertise and tenacity.
Post #14: I am not aware of this test. Please follow-up.
Post #15:
First point: True with the caveat discussed in my comment on Post #10.
Second point: Absolutely correct. It takes to faults to create ESD.
Third point: That is really a function of how strong the electrical field is and how sensitive the victim is to electric effects.
Fourth Point: Correct.
Post #16: See my comment on Post #3. I am not a doctor but "drowning" occurs when water enters our lungs. Electric Shock Drowning is a term that was coined to describe the physiological response to someone entering an electrical field and:
Post #17: That was Kevin Ritz. See my comment on Post #13 above.
Post #18: The current is not going to the seabed it is using the water column to return to its source e.g.; the N>G bond at the transformer secondary on the dock.
A galvanic isolator blocks cathodic protection current and passes AC that is present on the safety ground (green) wire.
Post #19: I think we loose about 10 to 15 people to ESD each year.
Caution against swimming towards a ladder is spot on.
Post #20: A sad and recurring story.
Post #21: Correct.
Post #22: Not really. The prohibition is to not swim in a fresh water marina that has electrical service. That said, you are spot on regarding the inverter or inverter/charger.
Post #23: Probably the best in depth discussion that I have seen and written at a level that is understandable.
Post #24: No comment.
Again, I created this post to try and get all of the participants on the same page...not to embarrass anybody. Please take my comments in the spirt in which they were made.
porman
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Excellent Charlie. Thank you
SteveK
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Charlie, I get a charge out of your posts. No comment on a tingle from lightning? How about a tingle while on the job, have you had any. Back in the day I could stop my watch by placing hand over it. Apparently rubber boots when wet inside conduct electricity when pant legs are wet too. 
Bonding may be another thread topic, it has been discussed. I will continue to buck the system and not bond AC ground to boat bonding system. My engine yes, as a precaution when I touch it. It is isolated from shaft & in water metals. You can swim around my boat.
Bonding may be another thread topic, it has been discussed. I will continue to buck the system and not bond AC ground to boat bonding system. My engine yes, as a precaution when I touch it. It is isolated from shaft & in water metals. You can swim around my boat.
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In response to CharlieJ, in my #14 statement above, I mistakenly described Nigel's procedure. The procedure is to put one lead from the multi-meter into the ground (not neutral as I indicated) on the dock receptacle and the other in the water. The figure in the book says salt water. Per Nigel " switch down to the lowest voltage scale: any reading indicates a serious leak." This is explained in the section Understanding and Troubleshooting Electrical Circuits with sub category Testing AC Circuits. Ref Boatowner's Mechanical and Electrical Manual - third edition page 153.
