Swimming should not be allowed at marinas. If you must swim at your dock for maintenance, unplug your ship to shore power during the swim.
There could be something in your canal that could hurt or kill you. Yes there may be a shark, gator or some overly zealous manatee, but there’s more of a likelihood that the threat is manmade.
There is a newer inherent problem with boats, docks and electricity. You have probably heard about this issue, if not let’s hope you don’t experience it first hand. The term is electrical shock drowning (ESD). The issue arises from electrical leakage. This is where electricity from dock power finds its way into the water that surrounds your boat. This could be a deadly situation if you are swimming in this water near your dock. To understand how this happens we have to remember a couple rules of electricity.
The first rule is that electricity must find its way back to the source, if it doesn’t, then no electricity. The second rule is that electricity will try every available path to get back to its source; and lastly electricity will always take the path of least resistance.
Now that we understand the rules, let’s explore how we run into problems with boats. It used to be that boats had a motor that we started with batteries. Often we would recharge these batteries with on board alternators when the engine is running. Or if you go way back in time you would charge the batteries by removing them and charging them in the garage. With modern advancement we now have shore power. Here is the scenario: We get back from a day on the water and plug our ship to shore power into our boat. No batteries to pull, just plug it in and all is good. Well, we hope. Not to over complicate things or get too in depth: with a boat we deal with corrosion and abuse that our house will never see. We have both alternating current (a/c) and direct current (d/c) when we are plugged into shore power. Occasionally this corrosive/abusive environment can create problems with the electrical system. If these two different types of power cross paths we can have a problem.
So now that we know what it is and hopefully have a better understanding of how it happens, what can we do to insure that we are safe at our dock?
- If you suspect you may have a problem, test the water, it’s easy to do. Go online and search “Preventing Electrical Shock Drowning.”
- Swimming should not be allowed at marinas. If you must swim at your dock for maintenance, unplug your ship to shore power during the swim.
- All electrical feed must be through a GFCI (Ground Fault Circuit Interrupter) just like the ones in your kitchen and bath. If unsure, have them checked.
- When you have your boat serviced ask that the electrical system be looked at for corrosion and loose connections and tested for any voltage leakage.
- Only use proper ship to shore cords, plugs and receptacles that where designed to work together.
- NEVER bypass a GFCI because of nuisance tripping. If your GFCI keeps tripping call an electrician to find out why, someone’s life could depend on it.
Now with all of that said, the danger of electrical shock drowning is more prevalent in fresh water but can happen in salt water also.
Thanks for reading,
Bryan Hayes
