Obviously, one owns a boat to have fun and provide enjoyment for family and friends. The last thing anyone would expect is tragedy. Unfortunately, boating accidents are an all-too-frequent occurrence. The good news is that most are preventable. In particular Carbon Monoxide poisoning (CO).
What exactly is CO? CO is an odorless, colorless gas that is created by the burning of just about any fossil fuel. The US Environment Protection Agency says, “Carbon monoxide (CO) is a colorless, practically odorless, and tasteless gas or liquid. It results from incomplete oxidation of carbon in combustion. Burns with a violet flame. Slightly soluble in water; soluble in alcohol and benzene.
Specific gravity 0.96716; boiling point -190oC; solidification point -207oC; specific volume 13.8 cu. ft./lb. (70oF). Auto ignition temperature (liquid) 1128oF. Classed as an inorganic compound.” Basically, you are not likely to smell it so when you are unfortunate enough to be breath large quantities of CO you probably won’t notice. What you will eventually notice is feeling sick and , depending on the concentration, die from high concentrations. The interesting part of CO poisoning is that it can occur in unexpected ways. Several years ago, when I was on patrol with the NYPD harbor unit, we pulled into a gas dock in Brooklyn to fill up the tanks. Normally the attendant was there to catch a line but, on this morning, there was no one on the dock. The attendant lived on a boat tied up to a bulkhead near the dock. We blew the horn and called out, but no one appeared, then one of my fellow officers checked his boat. Through the window he could see the gas dock attendant sprawled out on the bunk. They were boat dead. It was determined that a gas generator the attendant placed on the bulkhead had emitted deadly CO fumes that made their way into the cabin. Similar deaths are often reported when homeowners run a gas generator in their garage. Even with the garage door open fumes can make their way into the home.
One of the first things I did when I bought my Bertram boat was to sit down and read the owner’s manual front over to cover. Most of the information was a review but I was surprised to read that Bertram says the weather curtains on the back deck must always be rolled up when the engine is running. Th got me to do some research about CO poisoning in boats with the weather curtain down while cruising. The fact is that it happens all too often. CO tends to accumulate in space on and around your boat. Swim decks have been found to be particularly dangerous when swimmers hang onto them while the engines are running and creating exhaust. In a report from the Center for Disease Control (CDC) CO poisoning is described . “On June 1, 2002, a family of two adults and three children (two boys aged 4 and 12 years and a girl aged 2 years) and three friends went to a lake in Georgia to water ski. The ski boat was placed in an idling position while one parent put on a ski vest. During this time, the girl climbed over the back of the boat onto the swim platform (a wooden platform attached to the stern a few inches above the surface of the water) and lay in a prone position to push back and kick the water. In <1 minute, she became unconscious and unresponsive.
The girl’s father, a family physician, observed that her pupils were constricted, and her jaw was firmly clenched. She had a pulse but no chest movement. He performed rescue breathing; after 15-20 assisted ventilations, the child resumed unassisted breathing. Local emergency medical services (EMS) personnel were notified. Approximately 35 minutes later, EMS personnel arrived and started the child on 100% oxygen through a nonrebreather mask and transported the child to the local hospital. Nearly 3 hours after exposure, the child’s carboxyhemoglobin (COHb) level was 14.3% (normal: <5.0%). Back calculations of COHb levels estimated that her COHb level was 50%–57% immediately after exposure on the swim platform.” The interesting thing about this type of CO poisoning is that it occurred in what one might assume was the open air. Fortunately, the boy survived but it was an incredibly close call. Boat owners must be aware that it is never safe to keep the engine running when swimmers are in the water.
I recall talking with a boater who was bringing his thirty-foot cabin cruiser home in a heavy fog and a following sea. Evidently his exhaust was blown back into the boat causing two of his passengers who were down in the cabin to be overcome. The CO accumulated in the cabin could have easily been fatal.
One sure way to prevent the accumulation of CO in the cabin is to install a CO detector. And it you already have one to make sure it is working. CO can come from leaking exhaust rusted out muffler and several other sources.
This is the USCG recommend check list. “What to Inspect on your propulsion engine or generator set:
• Inspect and confirm that the engine(s) and generator(s) are properly tuned, and well maintained.
• Inspect each water pump impeller and the water pump housing; consider replacement if worn.
• Inspect and confirm that cooling system(s) are in working condition.
• Inspect and confirm that all hose clamps are in good condition and securely tightened.
• Inspect and confirm that there are no leaks around the cylinder head gaskets, exhaust manifold gaskets, water inject exhaust elbows, pipe nipples between water injected elbows and exhaust manifolds, and exhaust pipes, hoses, and fittings.
• Inspect and check the generator temperature sensor (if installed) to ensure that it has not been damaged by exposure to excessive exhaust temperature and that the sensor is still working properly.
• Inspect and confirm proper operation of the generator cooling water anti-siphon valve (if equipped). What to look for includes:
• Exhaust leaks
• Cracks in hoses, pipes, and components
• Black streaking (this can mean loose parts are allowing exhaust to escape)
• Corrosion in hoses, pipes, and components
• Corroded pipe nipple on exhaust elbow (move the elbow to check for looseness)
• Change in exhaust sound
• Change in exhaust smell in the engine room or boat interior (CO is odorless, but may be mixed with other exhaust gases)
• Check for pitting, pinholes, and cracks or loose rust at the ends of pipe nipples and thread roots
• Replace any component that is cracked, charred, or deteriorated.”
You can never be too careful regarding the dangers of CO poisoning on your boat, your car or in your home. It is the silent killer lurking wherever there is a flame.