Hot Docks & ESD - Electric Shock Drowning

[electricaldoctor]

Several years ago, my marine surveyor made me aware of this and I have made my fellow dock mates aware of this ever since. I have also asked my marina owners to post it on their web-site every year. http://marinesurvey.ca/hot-docks/

 

[MiLoII]

Thankfully my marina has a large notice posted at the entrance of every pier. Yet I remain amazed to see people in the water in the marina and also by the fact that so many are still unaware. So always good to raise awareness. Thank you for the posting.

 

[hillsideshortleg]

It's nice to know that there is a very easy way to check for this. As an electrical contractor it scares the crap out of me knowing how easy something like this could happen. There is a lot of moving parts on the marina docks I have been on and also a lot of connections. All possible points of failure. Maybe it's just a north Idaho thing but I think there are a lot of old docks with old outdated electrical parts all over.

 

[Gofirstclass]

When we took our boat down to Portland, OR a few weeks ago we stopped at Hood River Marina. They had used a stencil and painted a warning about ESD on every one of their docks.

It would be good if every marina did that.

 

[electricaldoctor]

Spread the word folks. There will be ground fault issues at one time or another for various reasons. They may not have anything to do with your boat, but could be originating from your neighbour's boat. If you must go in the water for one reason or another, take a moment and shut off the power in the immediate area. We all need to be aware of the consequences of potential stray currents in the water. Keep your family safe!!

 

[Woody]

Spread the word folks. There will be ground fault issues at one time or another for various reasons. They may not have anything to do with your boat, but could be originating from your neighbour's boat. If you must go in the water for one reason or another, take a moment and shut off the power in the immediate area. We all need to be aware of the consequences of potential stray currents in the water. Keep your family safe!!

I wonder how far away a fault could be and still cause a problem, any guesses?

 

[electricaldoctor]

That question is above my pay grade and when it comes to human life, I choose not to guess.

 

[k9medic]

My 6th grade son did a science fair project on ESD and measured current and dissipation based upon salinity.

Two weeks ago an electrician who owns a boat at our marina "probed" the waters after finding some significant pitting on his metal parts.

We had 4 volts AC and 1 volt DC in the water in some areas.

 

[Woody]

That question is above my pay grade and when it comes to human life, I choose not to guess.

I asked that question because I was wondering if the following statement, which is good advice, might also give a false sense of security, especially in the marina environment.

If you must go in the water for one reason or another, take a moment and shut off the power in the immediate area.

 

[electricaldoctor]

That was indeed a good question, but I don't have a definitive answer. A few years ago, I had to retrieve my prescription sunglasses and I had the power to my dock shut down for about 15 minutes and felt safe with that precaution. I suppose that the distance would be proportionate with the size of the stray current. Hopefully, somebody smarter than me can better answer your question.

 

[Boater420]

We have divers cleaning bottoms all day in our marina and all over Florida for that matter of fact. I know for sure they don't turn my power off, or the neighbors before they go in and start cleaning. How do they stay protected? I've never heard of any divers being electrocuted? Just curious why it's not a concern for them.

 

[Blueone]

Salt water's mineral content is more conductive than the human body. Electricity takes the path of least resistance.
I am sure you must have the same problems with shorting electricity in water...you just don't get electrocuted

 

[electricaldoctor]

We have divers cleaning bottoms all day in our marina and all over Florida for that matter of fact. I know for sure they don't turn my power off, or the neighbors before they go in and start cleaning. How do they stay protected? I've never heard of any divers being electrocuted? Just curious why it's not a concern for them.

I suspect that they are not aware of the potential risks at play here. Do your own research & make your own decisions. http://www.electricshockdrowning.org/

 

[Boater420]

I suspect that they are not aware of the potential risks at play here. Do your own research & make your own decisions. http://www.electricshockdrowning.org/

It seems that it doesn't happen in salt water as Blueone mentioned earlier.

Salt-water is anywhere from 50 to 1,000 times more conductive than fresh water. It's not that the divers here in Florida aren't aware of the risks, there ARE no risks for those in Salt water.

I feel like the website link provided in the original post didn't do enough to explain that there is no danger of this happening in salt water. After reading the website, I was left thinking this happened around all marinas. Which then made me wonder why I wasn't reading about more divers being electrocuted here in Florida.

The BoatUS website does a much better job of explaining the dangers of ESD and where they exist.
https://www.boatus.com/seaworthy/magazine/2013/july/electric-shock-drowning-explained.asp

 

[electricaldoctor]

It seems that it doesn't happen in salt water as Blueone mentioned earlier.

Salt-water is anywhere from 50 to 1,000 times more conductive than fresh water. It's not that the divers here in Florida aren't aware of the risks, there ARE no risks for those in Salt water.

I feel like the website link provided in the original post didn't do enough to explain that there is no danger of this happening in salt water. After reading the website, I was left thinking this happened around all marinas. Which then made me wonder why I wasn't reading about more divers being electrocuted here in Florida.

The BoatUS website does a much better job of explaining the dangers of ESD and where they exist.
https://www.boatus.com/seaworthy/magazine/2013/july/electric-shock-drowning-explained.asp

Excellent explanation. Thank you for posting. All you salties can exhale now. The rest of us fresh water boaters need to be aware of the potential risks involved. There probably should be a 'Sticky' for this.

 

[Blueone]

I got curious and started reading up on the subject of salt water electrocution and I just wanted to note this so you didnt think it was 100% safe in salt water.... not that your ever 100% safe in salt water

Here is the excerpt from the article. (Same one Boater 420 posted above)
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 is electrified.

 

[RollerCoastr]

An ESD happened in Lake Erie last June. First a family's dog fell in and struggled, so the Dad jumped in to get him, but he struggled, then their 19 yr old son jumped in. The son died.

Signs went up in marinas throughout the area. It was sobering to say the least. Friends of mine with dogs and teen-agers bought a floating alarm. We should probably have several on each pier in every marina...

 

[electricaldoctor]

It seems that it doesn't happen in salt water as Blueone mentioned earlier.

Salt-water is anywhere from 50 to 1,000 times more conductive than fresh water. It's not that the divers here in Florida aren't aware of the risks, there ARE no risks for those in Salt water.

I feel like the website link provided in the original post didn't do enough to explain that there is no danger of this happening in salt water. After reading the website, I was left thinking this happened around all marinas. Which then made me wonder why I wasn't reading about more divers being electrocuted here in Florida.

The BoatUS website does a much better job of explaining the dangers of ESD and where they exist.
https://www.boatus.com/seaworthy/magazine/2013/july/electric-shock-drowning-explained.asp

After watching a video attached to the Boat US link, they stated that there are a lot fewer ESD in salt water. They did not state that there are no risks in salt water. They went on to say "Do not jump into the water at any marina". Draw your own conclusions.

 

[dvx216]

They do make monitors you just threw in the water that tells you there is voltage in the water. Water voltage protectors 42500 sold at home depot and amazon for $149.00 .

 

[Little Ducky]

Do they make portable shore power 30 or 50 amp GFCI's that can be placed between the power source and the boat cord so at least you know your boat is not leaking power into the water?