Today, I read a news story about a boat that exploded at boat ramp in Hernando County Florida back in June. Out of the 5 people on board at the time of the explosion 4 were injured and two juveniles were airlifted to a local hospital with non-life-threatening injuries. In fact, the picture I used for this piece is the actual picture of the boat that exploded.
Why did the boat explode? The most likely cause was fuel vapor.
Fuel vapor, and more specifically, gasoline vapor is the number one cause of recreational boat explosions.
Not knowing about the dangers of fuel and its associated vapors, one would have to be living under a rock at the bottom of a deep ocean. Therefore, my point with this post is not to educate or lecture the obvious; but it may turn out that way (sorry).
Coincidentally (and yes, this is a shameful plug for my practical boating education program), I cover, in detail, the "does and don’ts" of boat ventilation and how to properly and safely fuel your boat. Some of my writing in this post includes some of that curriculum.
For those of you that have completed a boating certification course; you were introduced to the topic of boat ventilation systems. Hopefully, you all have put what you have learned into actual practice.
For those of you that were not required to complete a boating certification course (because you were born prior to January 1, 1989); listen up, the information I provide is essential to ensuring that the safety of you, your passengers and your boat; you don’t want to make the local news or become a statistic.
For those of you that own boats with outboards, don’t think you are off the hook for these types of accidents... In fact, the boat explosion that I referenced earlier was an outboard.
For the purpose of this article, I am only referring to recreational boats that have gasoline engines; such as electrical generators, wenches or boat motors. Diesel fuel and compressed gaseous fuels (LPG, CNG, etc.) are not addressed in this article.
Furthermore, I am only referring to boats under normal operating conditions. Boat’s with fuel or fuel systems issues and or general maintenance issues (and what you need to do to fix them) is not the focus of this article.
Did you know that gasoline in its liquid form does not burn?
That’s right, you read that correctly.
Well, if gas doesn’t burn, what does?
Gasoline's vapors.
In my attempt to avoid a chemistry lesson and provide a simplistic (albeit extremely crude) explanation; gasoline in its liquid form is designed to vaporize (turn gaseous) at an extremely low temperature; negative 40 degrees Fahrenheit (-40° F) to be precise.
Therefore, -40° F is gasoline’s flashpoint, the temperature at which the liquid gasoline converts to vapor.
Additionally, gasoline vapor was designed to retain and contain a very-high density of its incendiary compounds (compared to other combustible liquids), which is why gasoline is extremely flammable.
Due to the very-high density of gasoline’s vapor, it is heavier than the air around it; and therefore, will always accumulate and collect in the lowest places. Therefore and most importantly, the presence of liquid gasoline is continually producing vapors. These vapors, if not properly contained, will descend and distend to the lowest point(s) of the area.
Therefore, we now know that gasoline, in is liquid form, is always and consistently producing very dense and very flammable vapors.
Did you know that the normal operation of your boat engine is also a main source for gasoline vapors?
During normal operation, the boat’s engine is igniting the fuel vapors which makes the engine run. Once the engine is turned off, the leftover unused vapor in the engine(s) will flow out of the carburetor and collect in the lowest part of the engine compartment. This is why venting your boat before every use is an absolute requirement.
It is my opinion, failure to properly vent the engine compartment prior to starting the boat engine is the most likely cause for a boat explosion.
Outboards
For those of you that own boats with outboards do have a fundamental risk of gasoline vapors (albeit much smaller than inboards or stern boats). However, it does happen, which is the case of the boat explosion story I referenced at the beginning of this article.
Outboard boat owners should periodically check for the presence of fumes in their bilges and other enclosed spaces. If the smell of gasoline is present, you should ventilate the bilge or other compartments before starting you boat; or, use any battery or electrical devices.
As we have learned, gasoline is constantly vaporizing; and since the vapors are heavier than air, the fumes will not float up and away. Instead, they float down and around. Therefore, it is a good idea to regularly check the bilge and enclosed spaces on your outboard boats for the smell of gasoline; and if you do smell gasoline, you have an issue that needs to be addressed immediately.
Regulations
For those of you that did not know, there are federal (and quite possibly state) ventilation regulations that boat manufacturers and boat building hobbyists must adhere to when equipping a boat with an inboard or sterndrive gasoline-powered engine.
For most of you, the boat you own was built by a manufacturer. Therefore, we can safely assume that all the required ventilation regulations were adhered to WHEN THE BOAT WAS SOLD NEW.
Used boat owners, should validate that the ventilation requirements of your boat were not tampered with or altered by the previous owner(s). While tampering and altering a manufacturer‘s ventilation installation is highly unlikely, used boat owners should perform a basic inspection of the ventilation system to ensure it meets the manufacturer‘s original design and use of components.
Speaking of ventilation systems, used boat owners should also validate the boat’s fuel system to ensure no tampering or alteration was conducted by the previous owner to ensure the fuel system meets the manufacturer‘s original design and use of components.
And while we are on the subject of tinkering, repairing, improving and replacing…
Any battery operated or electrical device (especially if the device is automatic such as a bilge or sump pump) should be certified “ignition protected!” If the last boat owner was cheap, they could have gone to the local home improvement store and bought a standard pump that will do the job nicely, but, could also easily blow up your boat! Devices, parts and components that have electrical contacts (electrically operated switches) that energize or make electrical contact for an "on" state can (and often do) create a spark… And as we have all learned, a spark will easily ignite gasoline vapors.
Therefore, you should check the engine room/compartment, bilge or other enclosed spaces susceptible to accumulating gasoline vapors for any non-marine non-ignition protected devices.
Maintenance
Part of responsible boating includes routine maintenance checks of your boat and everything associated with it. Boat owners should perform a routine inspection of your ventilation system(s). I define routine as at least once a month.
Boats built now-a-days can stay in operation for a very long time; and while certain boat components are designed to last practically forever (e.g. fiberglass hulls) other components and materials do deteriorate and fail over time.
Ventilation hoses, fuel lines, connectors, fittings, valves, switches, moving components (bearings, gears) are all subjected to heat, vibration, friction, stress, bends/twits, environmental conditions and general wear and tear. These types of components will eventually fail their intended purpose.
Rubber hoses and rigid plastic lines become hard and brittle over time; and that degradation accelerates if the hoses and lines are exposed to the sun. In fact, you should be seriously considering replacing your hoses if they are older than 10-years from the date stamped on the hose.
Fittings and connectors become corroded and rusted. Valves and stopcocks become stuck. Ducts and conduits become flimsy and fragile. All these things can cause the critical boat components to fail; leading to leaks or loss of functionality; and that leads to trouble.
For example, an inspection might uncover a stuck or faulty fuel shut off valve; or, a ventilation duct not properly secured to a fitting or has a big hole in it from boat vibration. A few years ago, I uncovered that my vent duct had a huge hole due to a crappy installation attempt of an aftermarket speaker that tore the duct material.
How many of you have asked this rhetorical question…?
“Why in the @#$%! world would a boat designer put that thingamabob in that @#$^%@! location!”
Often with fuel and ventilation systems the location of these systems that you should routinely inspect and/or repair are practically impossible/improbable to get to. Nonetheless, this cannot deter you from doing your due diligence and inspect (or repair) these critical boat systems.
One suggestion for hoses and lines that you can’t see (but still reach) is to feel the entire length of hose (and fittings and connectors) with your hand; or, you can use a clean shop rag/towel. If you smell gasoline or feel/see moisture, you need to investigate and fix the cause.
Okay, enough about boat maintenance; makes my head hurt just typing it.
The reason I bring up maintenance issues is simple. Boats with gasoline-based engines potentially will have some existence or slight smell of fuel/oil under normal operating conditions.
HOWEVER, fuel and ventilation systems that have defects, weaknesses, deficiencies or failures; exponentially increases your chances of KABOOM!
Therefore, I am going to say it again… “Venting your boat before every use is an absolute requirement.”
BEFORE YOU START YOUR BOAT
BEFORE YOU START YOUR BOAT
BEFORE YOU START YOUR BOAT
Do I need to type it one more time?
BEFORE YOU START YOUR BOAT, you must ventilate your engine/fuel compartment for a minimum of four (4-5) minutes (That’s almost the length of two of your favorite songs!); or follow the manufacturer‘s recommended venting procedures, whichever is more appropriate and absolute in properly venting.
In fact, I would highly recommend that you put “ventilate” and “vapor check” on your daily pre-boating check list.
Outboard boat owners, you should frequently perform the sniff check in the bilge and other enclosed spaces; To be fair, the risk of vapors accumulating on outboard boats under normal operating conditions, used frequently and no equipment, device, part or component issues is very low.
After 4-5 minutes of ventilation and BEFORE YOU START YOUR BOAT, perform a simple smell test in the engine compartment and/or fuel compartments (if applicable). God gave you that nose for good reason.
When you perform a sniff test, you should not smell gasoline; and it is okay if you smell a very slight hint of fuel/oil smell. Your nose will know the difference between a slight hint of fuel/oil smell and the presence of gasoline vapors.
If after ventilation you smell anything stronger than a oh-so-slight hint of fuel/oil… DO NOT START YOUR BOAT ENGINE NOR USE ANY BATTERY OPERATED OR ELECTRICAL DEVICES.
If after ventilation you smell gasoline, you most likely have a fuel leak, the presence of liquid gasoline or your ventilation system is not working properly. Whatever you do next, DON’T START THE BOAT. You need to address the issue causing the strong gasoline odor.
Something to Think About:
While this is not typically seen with stern-drive boats operators, inboards boat operators tend to use the available space in the engine room/compartment for storage. It’s not a good idea to take up open space in your engine room/compartment for storage.
Manufacturers design engine rooms and compartments to meet federal regulations requiring sufficient open volume space.
Therefore, the moment you start storing items in the engine room/compartment, you are lessening the amount of sufficient open volume space, which will cause vapors to accumulate and concentrate faster.
In addition, stowed items not properly stowed, could interfere or damage with engine room/compartment components and systems resulting in performance issues or failure.
At this point, I think I have given the reader plenty to think about regarding ventilation.
I had planned to address safe fueling procedures as well; however, I will save that topic for another post.
Remember to VENT and keep safe!
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