Shocks & Electrocutions at Marinas and Docks

13 replies [Last post]
meby's picture
Joined: 2012-04-17

This type of tragedy is reported far too many times thoughout the year. It's especially difficult to read a report like this that involves a young child (The Case of the Floating Dock). What can we do as a professional community to help eliminate these unfortunate accidents and better protect the public?'s picture
Joined: 2013-11-22

You can't help stupid! If you look at most of the technology products introduced into the code like GFI, AFCI, Smoke Detectors, CO2 detectors ECT and everything else we have by code enforcement, many people never do get get their property inspected or even reviewed by professionals. Many could be eliminated or reduced if people understood how it all fits together.
Look at most fires by space heaters you will see that primary heating was defective and maybe off or the outlet that failed was most than likely a loose fitting poorly contraction to the plug. Like most things in our society we can not prevent everything.

afriedman847's picture
Joined: 2013-10-10

I agree this is tragic and unnecessary. The more detail oriented we are and the more attention we pay to safety procedures, the better. Can't stress this enough.

Bearfoot's picture
Joined: 2014-03-03

For the past 10 years, I've been preaching of a way to prevent these occurrences. Yes, it is possible. But there are no warning signs that danger exists.
The only way to address these issues is to install a device which continuously monitors for dangerous voltage conditions and alerts people if or when they exist.

Wye_Delta's picture
Joined: 2014-03-26

Part of the problem is the local AHJ doesn't want and/or know what to do because of lack of guidance. NFPA 70 stops at the shore-side receptacle, while USCG invokes nothing relevant and helpful, and ABYC is focused elsewhere. That is, there is a regulatory gap. Swimmer electrocutions are nothing new, and almost always, extremely sad events because often the victims are children. While the Tennessee proposal to mandate GFCIs is a step - it won't by itself be sufficiently effective to reduce this risk closer to zero where it belongs. Only by using isolation transformers fed from a GFCI branch circuit, together with continual leakage monitoring, AHJ initial inspection/approval and periodic inspection, etc can the likelihood for the numbers of such events be reduced to near zero.

mike4355's picture
Joined: 2014-03-26

I suspect that many of the reported strange cases of drownings are also caused by wiring issues. A person dives into the water, swims to a metal ladder, and receives enough current to cause cardiac arrest. The autopsy will show water in the lungs, ergo death by drowning. More regulation is very much needed.

mike4355's picture
Joined: 2014-03-26

RE: Comment by Wye-Delta; Absolutely agree with your post. I think a balanced line approach with continuous ground fault leakage monitoring is the answer.

Submerge's picture
Joined: 2013-11-21

The safety device should quickly eliminate the fault. Best case is to use a GFCI. In saltwater this may be impractical due to the higher conductivity of the water. In this case, a GFP up to 100ma trip can be used. Our USCG study showed that if less than 100ma is leaking into the water, a lethal voltage gradient will not be established around a boat where people would be in the water.

The best practice is to NOT swim around docks using AC power, period. For those that might fall in, following codes and standards will provide protection in most all cases. Check out Article 555 in the 2011 NEC. GFPs are now required in marinas for boat power!

Submerge's picture
Joined: 2013-11-21

I take exception to the poster who commented that the USCG and ABYC are essentially doing nothing in the effort to make it safer around boats and docks using electricity.

The USCG funded a grant study published in 2008 that studied the hazards of electricity in the water around docks, and offered strategies to mitigate same. They have engaged in the education effort in this area.

ABYC (The American Boat and Yacht Council) has been one of the most proactive organizations on the scene. They were the ones who managed that aforementioned USCG study. They also improved their standards in 2008 to require ground fault protection on boats. They are strong sponsors of many efforts to educate the public in this area. And they educate the marine technical community including those designing, building, and repairing boats.

The number of people who are aware of the dangers associated with using electricity at docks, marinas, and boatyards has increased dramatically in the past few years due to the efforts of these organizations. Their efforts are actually saving lives.

cscee's picture
Joined: 2014-06-12

No individual's dock or marina with power should allow swimming within 500 feet of the dock. Warning signs should be posted, and marinas and dock owners must inspect their electrical systems at least annually. GFCI protection must be mandatory.

sofiakleeman's picture
Joined: 2014-09-02

[quote=Bearfoot]For the past 10 years, I've been preaching of a way to prevent these occurrences. Yes, it is possible. But there are no warning signs that danger exists.
The only way to address these issues is to install a device which continuously monitors for dangerous voltage conditions and alerts people if or when they exist.[/quote]

Where have you preached from?

Gilwell.Bear's picture
Joined: 2014-11-19

I'm thoroughly frustrated by this thread. I'm a retired EE, I live on my boat, I cruise, and I try to educate other boaters on electrical safety issues like safely connecting to shore power, grounding, bonding, the concept of derived sources, the causes of dumping power into the water and Electrical Shock Drowning. I explain and promote ELCI for boaters. Here in this thread, you all bemoan the problem of Electric Shock Drownings, but you are all approaching this from the perspective of regulation and code enforcement. Important though those things are, they are not sufficient. The technology to address the problem is widely available, but we in the U.S. and North America do not have the public's interest and involvement. Your industry segment has to decide to get the lay public involved. The President of the ABYC considers the audience for his standards to be: 1) boat builders; 2) equipment manufacturers; 3) service technicians; 4) surveyors (analogous to home inspectors); and 5) lawyers involved in litigation. Note, no where is the humble boat owner/operator ever mentioned. But that humble boat owner is the guy doing weekend DIY electrical projects with inadequate knowledge, the wrong materials, the wrong equipment, and the wrong fabrication techniques for the application. He uses residential materials and techniques that are not applicable to boats or wet locations. And until he kills someone, it will actually work, just as it did in this case. The code industry segment will not make a serious dent in this problem until it decides that boat owners have a stake in it. Screw the revenue it derives by selling copies of code books and electrical standards to professionals. Invest some money in reaching and educating the lay DIY boat owner!

homestead's picture
Joined: 2014-12-30

So if a dock is served by a 120VAC line from a GFCI is it 100% safe downstream of that device?

kpro's picture
Joined: 2015-02-09

GFCIs do not provide 100% safety. However, if installed properly and tested regularly, they can prevent nearly all shocks to ground (ground faults).

When a GFCI protects you by tripping, I can personally verify that you still get shocked for a fraction of a second - which can cause a secondary accident like falling off a ladder.
Also, a GFCI will not protect you from a line-to-neutral shock (you are in the circuit like a light bulb) or a line-to-line shocks. These shocks typically happen to electricians or overconfident handy persons.

Also, studies show that many residential GFCIs are damaged or worn out (some are 40 years old) so people are plugging into non protected outlets. GFCIs manufactured after 2006 are superior to the old models.

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