The lakes are warming up and for those living where fresh-water boating and swimming are favorite summer activities, boats and docks are getting spruced up for the season. There is one aspect of your boat safety, however, you may be overlooking – the electrical system on your boat and dock. Today’s boats are filled with electronic gadgetry to entertain us, help us navigate, keep us warm and our drinks cold. Sometimes our docks are lighted, have boat lifts, or have outlets on them for convenience. But if your electrical systems have any faults you are unaware of, you may put yourself or others in the water in danger of a little-known event known as Electric Shock Drowning (ESD).

In a nutshell, ESD occurs when our salt-laden bodies encounter an electrical current in fresh water. As we are better conductors than the water, and electricity is always seeking the path of least resistance, it moves through us and can be fatal. In lower doses (say 15 to 30 milliamps) it can cause muscle paralysis which may lead to drowning, and in higher doses (as in cases where victims have come close to or touched electrified metal ladders in the water) the jolt can cause an immediate cardiac arrest.

Marinas are of particular concern because there could be many sources of electricity in the surrounding waters. Even if it is safe when someone jumps in, the water could turn deadly at any moment if any one of the boats throws power to a faulty line. The first sign is usually tingling in the extremities or a feeling of muscle numbness. If you can, swimming away from a boat or dock (against most people’s instincts) and moving to shore is your best chance of survival. If you see someone in the water suddenly go limp, do NOT jump in immediately to rescue them (again against most people’s instincts) as you may become the next victim! If you put a toe in the water and feel a tingle, shut down all power sources and throw the person a floatation device. ALL marinas need to disallow swimming from their docks as a precaution.

If you have electricity (or are thinking of adding electricity) on your dock, make sure it is installed correctly. “If you need electricity on your dock, hire a licensed electrician and make sure the wiring meets the requirements in NFPA 303 and NEC 555. If your dock is already wired, hire an electrician to check that it was done properly. Because docks are exposed to the elements, their electrical systems should be inspected at least once a year.”[1] If you usually run a power cord out to the dock to charge your boat’s batteries, a safer option is to remove them and charge them away from the water – especially if your dock is routinely used for swimming. GFCI’s are important, and all electrical outlets on your dock should have GFCI, but they are no guarantee against shocks as most ESDs occur when the ground line is damaged! Make sure you have ground fault protection on the source breaker connected to the ground line for your dock, and make sure it has been installed by a licensed electrician.

Remember any part of the equation can fail, so the best piece of advice is to shut down any electricity to your dock before allowing swimming, and enforce strict “no horseplay” rules on your dock to avoid anyone accidentally falling into the water when the electricity is turned on.

Swimming pools are also potential ESD hazards. Pumps, lights, filters – they all run on electricity. Making sure all your electricals are plugged into a GFCI is only one piece of the safety puzzle. In May of 2014, this video was uploaded onto YouTube showing surveillance footage of a swimming pool at a condominium complex in Hialeah, FL. A child grabs the metal stair railing and instantly goes limp. Children are seen scrambling out of the pool while an adult pulls the unconscious child to safety and then goes back for a second who had also made contact with the pole, the rescuer himself falling as he is hit with the current. While everyone affected in this instance was released after 4 days in the hospital – the outcome could have been far worse. The narrator of the footage tells viewers it was “unconnected ground wires in the pump house” which caused the potentially deadly electrical current. Regular checks of all electrical equipment should be a routine part of owning or operating a swimming pool.

There are devices you can purchase which monitor the water, and they seem like a good idea, but the fact of the matter is the water can become charged at any time. So if the device says all is good and you jump in the water, it could detect something is wrong while you or your loved one is swimming, and by then it may be too late. They are useful in warning swimmers to stay away (a 200 ft radius is the minimum safe distance) if they are not in the shock zone, and would be useful to warn rescuers not to jump in to save someone who has been shocked, but should not be used in place of common sense practices like turning off the power to docks and boats before swimming in the area.

The exact number of victims of ESD are unknown, mostly because most accidental deaths in the water are ruled as drowning, which is technically true in many ESD cases after the victim becomes paralyzed by the electric shock.

So what is the answer when you are enjoying fresh water boating and swimming this summer? Use common sense:

  1. Never swim off the docks or the backs of boats at a marina.
  2. Never swim within 100 feet of any dock that has electrical power.
  3. Make sure all electrical to a boat or dock has connected and undamaged ground wires
  4. Turn off all power to boat or dock before swimming in the area
  5. Never jump into the water if you see someone in the water go suddenly unconscious before turning off all possible power sources
  6. Know CPR and encourage marina owners to have Automated External Defibrillators (AEDs) available and accessible. AEDs are commonly used in resuscitations of both drowning and electrocution events.

For more information on ESD, how to prevent it, and what to do if you are ever in an ESD situation, visit http://www.boatus.com/seaworthy/magazine/2013/july/electric-shock-drowning-explained.asp