I've read a number of your explainations of this and other electrocutions near marinas. It is obvious that it is a known problem (posted signs), but most times seems to come from vessels that may be out of the control of the marina. Many of the problems appear to be even unknown to the owners of the vessels. As a security alarm dealer, we protect people from many dangerous conditions, and I am curious why there are not voltage sensors in the vicinity of the actual docks themselves, to alert the marinas of a dangerous condition when the vessels connect to shore power. It would appear that it should be a simple sensing of current in the water vs a known ground system, with an audible alert system that would automatically activate, and potentially shut down the dock shore power (even if it took out multiple docks), till the offending vessel was identified. Your thoughts ? Tom

It is truly a shame and tragedy that this event took place. I question as to "why be the owner of the marina allowed (knowlingly) to exhibit such a sign. Why didn’t the city, county, state, etc. take charge of the situation long before this episode occurred? In my 36 years in the electrical industry (most of that as an electrical contractor) I have found that even the most educated electricians are so un-aware of the potential and lethal effects of a improperly grounded system, as a grounded conductor carries back,"1/2 of the 110 v/a to the source generation point in the earth at the speed of light. There is a code for grounding but what about the emf effect on the electrode and earth it comes in contact with or the ufer ground? I have found glass formations around the electrodes making it useless thereby allowing the current to pass through without causing an overload situation which would interrupt the breaker or fuse, inline as there was no ground but only a "resistor" in place. I have been waiting and looking for the time when there is a minimum code enforced with which mandates "a minimum of a 3 ohms resistance (tested) on all grounded systems" so as to ensure the safety for all concerned. Let’s be proud of or work and contribute to the safety of the industry instead of just doing it without knowledge and concern other than a pay check. Thomas Frye President Frye Company Electrical Contractors.

Truly tragic. When will boatowners and homeowners stop being so d@mn cheap and hire a real bona fide electrician to make the necessary repairs? Is the life of a loved one worth the $100 you saved by doing it yourself?

A followup on the results of the investigation would be appreciated. The better we understand this type of incident, the more we can do to prevent it happening again. You had a series of newsletters a while back on this subject. One key point made then was the difference in danger between fresh water and salt water, i.e. fresh water being more dangerous because the body's conductance is greater than fresh water and provides a lower resistance path for current flow.

Would / could this same thing happen if the houseboat power was provided by some type of inverter or photovoltaic system? I am assuming that the houseboat was not plugged into shore power but using its own generating system. This makes you think twice about swimming near a houseboat when the generator is running. This is truly a very unfortunate accident

My family always had a boat on Lake Erie in Ohio and we motored to many different docks around the lake. My father always carried a outlet tester with him on the boat and he would test the outlets for shore power before he would connect to them, checking polarity and the ground. There were several times that he found a problem due to misswiring or corrosion and would contact the Dock Master to get it corrected. We always swam around the boat so thanks to him he probably saved several kids lives around the lake. Thanks Dad or Wally to his friends.

I am sorry the woman died. However, NEC 90.2(B) specifically exempts watercraft from coverage by the NEC. I hope the family sues the manufacturer out of business.

This is so sad. As a father of three wonderful daughters, my heart weeps for her parents.

Mike,

Is there anyway you can forward this on to other area Marina's in Kentucky? Or for that matter any other marina's in general no matter where they may be located?

I can try to obtain some email addresses to you if it helps. I don't know what rules or regulations a dock owner has to obide by and hindsight is 20/20, but if the dock owner had simply shut his facility down until the electrical problem was repaired a very young life could have been saved...

Thanks for your time,

Tim Caudill Electrical Designer

One thing that needs to be changed in National Electrical Code is to require marinas to use outlets that not only have an equipment ground but also a pilot wire for continuous monitoring of the equipment grounding path.

However, coming up with a safety relay that can tell the difference between a path provided by copper and a path provided by water could be tricky. Salt water makes the problem even trickier.

What is used in mines is a relay that looks for a diode that connects the pilot wire to the frame of the machine. If the pilot wire is open circuit the relay drops out and cuts the power. This feature can also be used for remote control of the power source, connection of motor thermostats, and so forth. If the relay sees both polarities of alternating current then there is a ground fault or power cross in the pilot wire and the relay locks out.

The previous technology was to use a wheatstone bridge with one of the resistors at the load end of the pilot wire.

To do a marina the safety relay would need to periodically send a high current pulse that would check the voltage drop in the equipment grounding conductor.

Had a something like this. A ground fault on a water heater cause a next door house cold water to become live because they shared the cold water service. Regards. Warren Knight. UK.

I had responded off duty as a firefighter/medic to a "man in pool" call,possible drowning. I was 1/2 mile from the call, responded in pov to find a screaming/paniced elderly woman behind a home with an enclosed pool. Her husband was in the water, face down. He was out of reach to me so I jumped into the water to immediately feel a near paralyzing "tingle" throughout my body. I grabbed the patient, kept his head above the water, and drug him to the pool side where I immediately exited the water and now with arriving engine company removed the now breathing man from the water. The pool lite had been worked on by a pool repair company earlier in the day. Later on, the husband and wife were going to go swimming- he jumped in and he groaned and becane incoherant. The power was disconnected at the fuze panel which stopped the "charging" of the pool/ Lesson learned: 1- consider power when a similar situation presents itself

2- communicate this potential hazard to all citizens who have pools, including :kiddie" pools near electric lites, etc. 3- include this training in basic rescue classes, firefighter curriculum, etc. 4- advertise on the media from local power companies similarly to what they do with downed power lines