Summertime = relaxation, family time, and fun in the water, right?
But things can potentially turn sour when people decide to swim too close to marinas and private docks. When not maintained, the electrical systems that provide power to watercraft have the potential to leak electrical current into the water.
(This article focuses on the dangers of electrical equipment around fresh-water marinas, but don’t forget about your swimming pool. Proper maintenance of your electrical equipment in that space is just as vital. See this news story for a reality check.)
When Things Go Wrong
Last month in Callahan County, TX, an 18-year-old man was electrocuted while pulling a disabled sailboat to shore. The boat struck power lines, which caused the line to contact the water and the electricity to make its way to the young man. He was transported to a hospital but died from his injuries.
Another young man died from possible electric shock drowning, this time in the Monongahela River in Pennsylvania. When he was found unresponsive in the water, a friend put on a life jacket and jumped in to help. The friend told doctors later that after he jumped in, he felt like he had been horribly shocked.
Electric Shock Drowning (ESD)
ESD is the result of the passage of a typically low level alternating current (AC) through the body with enough force to cause paralysis, rendering the victim unable to help himself / herself, and eventually resulting in drowning of the victim. Higher levels of AC current in the water will also result in electrocution. ESD has become the catch-all phrase that encompasses all in-water shock casualties and fatalities.
ESD Risk at Industrial Facilities
This is a danger facing not just the general public. Many industrial companies own and maintain docking facilities as well. Because they are moving and working around water, employees such as dockworkers, divers, and general contract workers are at risk for electric shock drowning if electrical equipment is not inspected regularly and repaired immediately after a problem is detected.
Electrical Standards in Outdoor, Wet Locations
The National Electric Code (NEC), Article 555, covers the installation of wiring and equipment at piers, wharves, docks, floating buildings… marinas, boatyards…docking facilities associated with one-family dwellings, two-family dwellings…and other areas that repair, berth, launch, store, or fuel small craft. (“Small craft” is not defined by the NEC but is based on NFPA 303, which lists recreational and commercial boats, yachts, and other craft that do not exceed 300 gross tons as small craft.)
(Previously, the NEC had exempted single-family dwellings from the requirements of Article 555. Note that is no longer the case.)
Article 555.9 includes GFCI requirements for boat hoists in marinas, boat yards, and floating buildings. All receptacles other than shore power require GFCIs. Article 555.35 lists specific ground fault protection for personnel and equipment at marinas.
Let’s go to NEC 210.8(A): In dwelling units, all 125-volt through 250-volt… single-phase branch circuits rated 150 volts or less to ground in the locations specified…[must] have ground-fault circuit-interrupter protection, with “outdoors” and “boathouses” as two of the locations on the list.
NFPA 303, Fire Protection Standard for Marinas and Boatyards, addresses the construction and operation of marinas and related facilities (boatyards, yacht clubs, and docking facilities), as well as in facilities where boats are stored on land. The standard includes maintenance of fire-fighting equipment and systems, and electrical wiring and equipment. NFPA 303 requires annual inspections of electrical wiring at marinas and annual inspections of boats that are plugged into the marina’s electrical power to check for stray currents.
In early 2015, the Tennessee State Fire Marshal’s Office began the first-ever inspections of the electrical wiring and equipment of Tennessee’s more than 300 public marinas and docks. The inspections began with the passage of Senate Bill No. 1954/House Bill No. 1892 – known as the Noah Dean and Nate Act. This bill’s intent was to “lessen the likelihood of electric shock drowning near marinas and boat docks.”
The laws in both states require GFCI’s to be installed at public docks and marinas and regular inspections to take place for each facility’s electrical supply (every year in Tennessee and every three years in West Virginia). Additionally, permanent signs must be posted warning people not to swim within 100 yards of the dock or marina.
Heading in the Right Direction
Steps are being made in the right direction, albeit at a slow pace, to address and regulate safety wherever electricity is close to a recreation or commercial water area. Product engineering can and should alleviate many potentials for human error during installation, but these innovations take time and money before they make it to market.
The responsible thing to do would be to have electrical systems regularly inspected by an electrician with current ABYC (American Boat and Yacht Council) Electrical Certification or by an ABYC Certified Technician to make sure the systems are operating safely, whether it’s at a public facility or a private dock.
Be aware of the dangers, educate others, look for signs of lack of electrical maintenance, bring those issues to the attention of the owner or manager of the dock or marina, and take precautions. It’s better to be safe than sorry.
Good Sites to Visit for More Info on ESD
NFPA video, The Hazards of Electric Shock Drowning: