I have heard that you shouldn’t swim near a freshwater marina with boats plugged into the dock’s electricity supply. Is this true? If so, can you tell me what a safe distance from the marina would be for swimming?—Richard Wilson, Carling Township, Ont.
Yes, it is true.
“With respect to swimming near marinas, the dangers are two-fold,” says the Canadian Safe Boating Council’s Ian Gilson. The first danger is obvious: “Swimmers run the risk of being run over.” The second danger is hidden: “There’s the risk of electrocution from improperly grounded power cables at the dock.”
Weekly Hack: Electrical safety tips for opening up
The same danger exists anywhere stray electric current can get into the water, for example, from the marina boats themselves, or, at a cottage, from a powered dock with lights that have been improperly wired. If the amount of current in the water is small, or the person is far from the source of electricity, a swimmer may notice “a tingling feeling caused by the stray current,” says John Gullick, the past chair of the CSBC. But it’s not necessarily going to cause injury. A high amperage of current, on the other hand, could paralyze or kill a swimmer: it’s called electric shock drowning. Even though marinas are required to have ground-fault circuit protection, “ESD is more likely in a marina setting because there are multiple electrical outlets,” says Gullick. All that said, staying 100 metres away is safe, he says. (Electricity dissipates over distance, just like ripples or sound waves.)
Could you void your insurance policy by DIYing electrical work?
Here’s the thing: ESD is a possible danger, and swimmers should know about it. But is it a common cause of drowning? The stats that we found suggest no. For example, the Lifesaving Society, which has been researching and reporting on drowning deaths in Canada since 1990, doesn’t currently report on cases of ESD. A possible reason why? The percentage of drowning deaths that ESD cases make up, compared to drowning deaths caused by, for example, not wearing a lifejacket while boating, isn’t significant enough to report.
10 cottage safety hazards you probably don’t know about
To learn more about ESD risks and how to stay safe, see Cottage Q&A, Spring ’18, or visit electricshockdrowning.org.
This article was originally published in the August 2025 issue of Cottage Life.
Related Story How to deal with flooded electrical
Related Story OPP hands out hefty fine to kayaker with no lifejacket
Related Story Video shows man saving bald eagle from drowning