Discover projects
News Post

Don't Swim in the Water: The Hidden Danger of Current Leakage


The danger in the marina is not the water itself but something invisible to the naked eye, hiding in the water. It is alternating current (AC) that has leaked into the water. With thousands of boats docked side by side, many of which may not have met safety standards and equipment on docks that are old and have been installed improperly or altered, there are many opportunities for current leakage to occur.

How do electric shock drownings occur?

Electric shock drownings (ESDs) occur when an electric current passes through a body causing paralysis of the skeletal muscles, respiratory paralysis which shuts down the lungs, ventricular fibrillation or full cardiac arrest. The most common occurrence is paralysis of the skeletal muscles. The swimmer becomes numb, unable to move their limbs to stay buoyant or swim to safety. This eventually leads to drowning in the water.  The current is strongest near the source of the leak and weakens in gradients the further out it moves. But even if you think that you may be far enough away from a boat or dock, you could still suffer an electrical shock.

Why are electric shock deaths more common in marinas and not in the ocean? It has to do with saltwater’s conductive nature. Water in the ocean contains salt and salt is 50 to 1000 times more conductive than freshwater. Human bodies contain salt but since it is less than the amount found in a saltwater environment, an electrical current in the water will move around the swimmer. The freshwater surrounding marinas lacks salt in the water. So the electrical current in the water will use the swimmer’s body to return to the ground.  

Electricity finds itself in the water due to faulty wiring or improper grounding of equipment systems near water. These systems are found on boats and docks. Examples that have been found are

  • absence of a safety ground
  • failure to separate the green and white wires or install green wires in the first place
  • reverse polarity

So why is it that swimmers cannot detect the electrical current in the water as soon as they dip their toes in? The reason is that electrical faults on boats are intermittent and occur when equipment is turned on on board. This includes air conditioning units, water heaters, electrical devices or something that is more likely to happen during the day, like turning on a light switch. It means the water can be safe one moment and then instantly electrified the next. There’s no time to react once you become paralyzed by the current. Current leakage affects about 13% of marina boats.

On docks, shore power equipment with faulty or old wiring and shore power cords that have fallen into the water, introduce an electrical charge into the water. It only takes current in the water that amounts to ⅓ of a lightbulb to cause a fatality and about 6V to cause paralysis. Electricity in the water is not only a concern for boat marinas, but also for houseboats and houses with their own private docks. From pets to humans, anything floating around the docks can be impacted by faulty wiring or current leakage from the docks or boats into the water.

Ways to eliminate current leakage

There are several ways to eliminate current leakage. One way would be to isolate the shore power system from the power system on the boat with an isolation transformer. An isolation transformer transfers electricity between a boat and the shore by using a magnetic field generated by electrical current, in place of shore wires that connect with boat wires. Using magnetic field transfer means that any stray current on the boat will return to its source on the boat instead of leaking into the water.

Another option that has been the standard in Europe, Australia and New Zealand for the last 30 years is the installation of ground fault protection in the main feeders and power pedestals. Ground fault protection shuts off current when the electricity output differs from the amount of electricity that is returning. This standard has eliminated ESD fatalities in those areas of the world.

The fire protection standard for marinas and boatyards in the US set by the NFPA (National Fire Protection Association) requires ground fault protection devices to be installed on docks that trip at 100 mA or lower. However, these devices are expensive to retrofit and maintain for large marinas. They require monthly testing and unfortunately are subject to nuisance trips in the marine environment. Unfortunately, this has led to low adoption and enforcement difficulties.

The ABYC made ground fault protection on boats part of the E-11 electrical standard. This means that all newly constructed vessels built to meet ABYC standards  must install Equipment Leakage Circuit Interrupters (ELCIs) that trip at 30 mA. So what about older boats?

Enter (the Water with) VoltSafe Marine.

VoltSafe has the solution. VoltSafe Marine is a marine shore power magnetic electrical connector, paired with a groundbreaking app, that addresses several issues with shore power safety. This includes eliminating arcing and detecting current leakage. With VoltSafe Marine’s powerful app, the company’s goal is to eliminate hidden corrosion and alert boat owners and marinas of current leaks that may be occurring. The goal is for VoltSafe Marine to become adopted as the safety standard and yield the results seen in Europe, Australia and New Zealand of eliminating electrical shock drownings.

VoltSafe CTO, Sanad Aridah, had the opportunity to meet and chat with members of ABYC (American Boat and Yacht Council) to learn about some of their pain points and discuss how VoltSafe Marine will address concerns around boating safety. VoltSafe Marine  will reduce everything from dock damage to fires from hidden corrosion, managing moorage fees and billing to eliminating current leakage. In the marine space, everyone from boaters, marinas and insurance companies are eager to see VoltSafe Marine become the standard in North America and the rest of the world.

If you own or operate a marina and want to improve safety for your marina and its boaters, email us at

Related posts

Keep learning

News categories