Nothing says summer fun like being on a boat, but boaters, swimmers and marina staff must be aware of the unique dangers in and around the water.

Electricity and carbon monoxide (CO) bring particular risks to the boating world. CO is a deadly gas that is odorless, colorless and tasteless. Often called the silent killer, CO is created when fuels such as gasoline, diesel, or propane do not burn fully. Another potentially silent and deadly hazard is electricity and water. Electric Shock Drowning (ESD) is the result of the passage of a typically low-level AC current through the body with sufficient force to cause skeletal muscular paralysis while immersed in water, eventually resulting in the drowning of the victim. Learning how to protect you and your family from these dangers will make your time on the water most enjoyable.

According to the Centers for Disease Control, all carbon-fuel engines on boats, including onboard generators, produce CO. The most common symptoms of low-level CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. Higher levels of CO inhalation can cause death. CO poisoning can also cause you to pass out and fall into the water and drown. A person who is sleeping or intoxicated can die from CO poisoning before waking and realizing you have symptoms.

Your local firefighters have a few recommendations to protect you from CO poisoning while you are on your boat. The first step to staying safe is to install CO alarms inside your boat and test the alarms before each trip. Whenever the CO alarm is activated, move to a fresh-air location right away and fully investigate the cause.

Larger boats, such as cabin cruisers and houseboats, sometimes have generators that vent toward the rear of the boat. This venting poses a danger of CO poisoning to people on the rear swim deck or water platform. Because of this danger, it is suggested that swimmers avoid the water near rear swim decks or water platforms. Since the exhaust from a nearby vessel can send CO into the cabin and cockpit of another boat, you should always dock, beach, or anchor at least 20 feet away. Traveling at slow speeds or idling in the water can also cause CO to build up in a boat’s cabin, cockpit, bridge and aft deck, or even in an open area. You should always keep hatches, windows, portholes and doors free from debris so exhaust can vent freely.

While CO may be the silent killer and present a hazard in the air and around the boat, electricity poses a silent threat in the water. Electric Shock Drowning can occur when marina electrical systems leak electrical current into the water. It is important to note that there is no visible warning or way to tell if water surrounding a boat, marina or dock is energized or within seconds will become energized with fatal levels of electricity.

According to Electrical Safety Foundation International, ESD can occur virtually in any location where electricity is provided near water, and the majority of ESD deaths have occurred in public and private marinas and docks. The typical victim of ESD is a child swimming in or around a marina or dock where electricity is present. The electricity that enters the water and causes ESD originates from the wiring of the dock or marina, or from boats that are connected to the power supply at the marina or dock.

In most circumstances, victims do not immediately feel electrical current when they enter or swim in the water around a marina or dock, thus giving the victims the false impression that it is safe to swim. Electricity enters the water when an electrical fault occurs aboard a boat. Often the electric fault occurring aboard the boat is intermittent. For example, the fault that places deadly current into the water may only occur when a light switch is turned on, or when a hot water heater, battery charger, air conditioning unit or other electrical device cycles on. Water can appear and feel safe and in a split second become energized with deadly electricity.

Even though ESD is more common in fresh water, salt water is not completely risk-free. The danger of shock exists wherever there is water and electricity. Depending on the level of the electric current, you may feel tingling or lose control of your muscles, suffer from paralysis and drown. The current can also trigger a fatal heart rhythm. Remember, there is no visual warning or other clue that water may be electrified, and it doesn’t take much electricity to cause drowning. In fact, as little as 2 watts can be fatal to a swimmer.

Like many risks, there are steps you can take to prevent this horrible tragedy from happening to you or your loved ones. The best preventative measure is to never allow swimming near the boat, marina, or launching ramp. It is also a good idea to have your boat’s electrical system inspected annually by a certified marine electrician. Ground-fault circuit interrupters and equipment-leakage circuit interrupters should be tested monthly to ensure functionality. Only use shore power cords that are UL-Marine Listed because they are safe to use near water. Household cords are never appropriate for a boat, at a marina, or on a dock! Verify the location of your main breakers on the boat and the shore power source so that you can respond quickly in case of an emergency.

In an emergency, disconnect the shore power at the breaker, throw a flotation device to the victim, and call 911. Remember to never jump in after someone who is experiencing ESD, because you may fall victim as well.

Your local firefighters are a great resource for learning more about carbon monoxide prevention in your home and on your boat. For more information about Electric Shock Drowning, visit www.esfi.org.

This column was written by Jane Perkins, Fire Safety Specialist for the Rhode Island Southern Firefighters League and Captain of the Watch Hill Fire Department. If you would like to see a question answered in this column, please e-mail her at askafirefighter@yahoo.com.