Electric Shock Drowning | Boat, Dock, Pool and Spa Electrical Hazards


Electric Shock Drowning | Boat, Dock, Pool and Spa Electrical Hazards

Electric Shock Drowning - Boat, Dock, Pool and Spa Electrical Hazards

Summer is the time of year when people go swimming. The waters are cool, calming, and full of diverse marine life.

Unfortunately, the fun can turn fatal.

There may be an invisible danger lurking underneath. Known as the “silent killer,” electric shock drownings (ESD) occur when electric current in the water incapacitates the swimmer long enough to cause drowning.

What is electric shock drowning?

It’s a danger that you can’t see, and you can’t smell. Usually by the time you feel it, the current can paralyze the body’s skeletal muscles, inhibiting the ability to swim or move one’s limbs (i.e. electrically induced cramp). The outcome in many cases is the drowning death of an otherwise healthy individual.

ESD can occur in swimming pools, spas, lakes, marinas, and other fresh water environments.

One minute, you are splashing and having fun, the next minute, you could be dead. The danger is real. Click here for a list of Electric Shock Drowning Incidents.

While there are many dangers associated with swimming, electrical hazards are often overlooked. Don’t underestimate the danger of electrified water.

Learn how to keep your family safe and avoid electric shock drownings and electrocutions!

Electrified Water and the Human Body

When there is faulty wiring and damaged electrical equipment near boats, docks, marinas, swimming pools, and spas, there is a chance that electricity can leak into the water supply. The effect of coming into contact with electrified water ranges from mild tingling to severe burns, cardiac arrest and death.

While it is hard to predict the exact effects of any given amperage, the table below demonstrates the probable effects on the human body during an electric shock of one second.

Current level(Milliamperes)

Probable Effect on Human Body

1 mA

Perception level. Slight tingling sensation. Still dangerous under certain


Slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary
reactions to shocks in this range may lead to injuries.

6mA – 16mA

Painful shock, begin to lose muscular control. Commonly referred to as the freezing current or “let-go”

17mA – 99mA

Extreme pain, respiratory arrest, severe muscular
contractions. Individual cannot let go. Death is possible.

100mA – 2000mA

Ventricular fibrillation (uneven, uncoordinated pumping of the heart.) Muscular contraction and
nerve damage begins to occur. Death is likely.

> 2,000mA

Cardiac arrest, internal organ damage, and severe burns. Death is probable.

  • NIOSH [1998]. Worker Deaths by Electrocution; A Summary of NIOSH Surveillance and Investigative Findings. Ohio: US Health and Human Services.
  • Greenwald EK [1991]. Electrical Hazards and Accidents – Their Cause and Prevention. New York: Van Nostrand Reinhold.

Source: Occupational Safety and Health Administration (OSHA)

How to Prevent Electric Shock Drowning for Swimmers

How to Prevent Electric Shock Drowning for Pool Owners

How to Prevent ESD (for Boat Owners)

How to Prevent Electric Shock Drownings (for Boat Owners)

Source: Electrical Safety Foundation International

If you have the money for a dock, boat or swimming pool, you have enough to ensure electrical safety.

Sign up for the Super Service Club for electrical safety inspections every 12 months.

Signs of Electrified Water

If you notice any of these signs, get out of the water immediately.

What to Do In Case of Electrified Water

If You See Someone in Electrified Water

Do not jump in the water to save someone. You could become a victim as well.

All of us at OnTime Service want to wish you a happy and safe summer! 


Call OnTime Service at 205-942-1405 to schedule your next HVAC, electrical, and plumbing service.

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