Electric Shock Drowning
Understand the Dangers Posed by Marina Electrical Systems
Drowning caused by leakage of shore power into the water is preventable. Learn more about problems with stray power and its potential for causing electric shock drowning.
Many visitors and boaters using marinas are surprised to learn swimming is prohibited at many of these facilities. We discussed several of the issues that cause Corrosion and Electrolysis damage to boats. One particularly aggressive cause for corrosion damage to vessels is stray electrical current being introduced into the water. We can all appreciate to cost associated with replacing an expensive propeller, but stray current poses another problem. Stray current being dumped into the water by a boat can and has killed those swimming too close to the leak.
What is electric shock drowning?
In the parlance of electricians, the low level leakage of shore power into the water can create high-energy potentials to materialize near metal surfaces in the water. Stray current leakage into salt water is less of a problem than power being discharged into fresh water. Salt water is a conductor; electrical current likes to travel to a ground. Fresh, clean water is a poor conductor. Alternating current introduced into fresh water forms an electrical field around metal objects in the water that can paralyze a swimmer. This is a dangerous situation that has caused many drownings. Post-mortem examination of the drowning victim will not link the cause of death to electrical shock. The only definitive evidence comes from witnesses of the event, reports of tingling sensations from contact with the water and other circumstantial factors. This means that many more people die from this factor than we can truly know.
What contributes to this problem?
Boat electrical systems have two distinct component systems that can be improperly wired. The first is the vessel grounding system. Grounding is electrical equivalent of a safety system. The grounding system is designed to carry this energy away from the user and allow it to discharge. Larger vessels have a bonding system. Bonding entails electrically connecting all metal surfaces of a boat in the water to each other. This is meant to equalize potential current across all metal surfaces. This can help reduce corrosion of these surfaces exposed to the water. Energized lines can fray, corrode or otherwise develop current leaks into these systems. Alternating current being dumped into the water in this manner will not trip a circuit breaker and you as the vessel owner also get to pay for the additional power consumption.
David Rifkin at Quality Marine Services has more information for boaters on this subject. Learn more about solving this problem in the article called Mitigate Electric Shock Drowning.
