Marine Gasoline Engine Explosions
Recently, one of the blog I follow Loose Cannon, published an update on a fatal accident - involving a 1999 Sea Ray 340 Sundancer Pajivo - that occurred May 2020 in Missouri. I try to follow marine accidents and causalities closely in order to raise my awareness of potential dangers out on the water. These disasters are often terrible, sad tragedies but I believe that the best thing we can do as owners, captains, and operators is learn, or remind ourselves of the hazards that - rarely - but do occur on the water in order to keep ourselves and our passengers safe. This event is a cruel reminder that asoline engines, when installed in an inboard configuration, on boats are safe when they are maintained and operated according to the manufacturer’s recommendations and instructions; which are probably plastered all over a bulkhead accompanied with scary-looking diagrams. However, because their engines, tanks, and fuel hoses are contained in a closed bilge, disaster can occur when fuel systems go unmaintained and begin to leak.
An example of a Sea Ray 340. They are beautiful, spacious, comfortable boats.
This accident hits particularly close to home for me. In college, I spent a lot time on a Sea Ray 340 of this vintage on Lake Champlain. It was a stunning boat - comfortable, spacious, and fast. The cockpit and interior are laid out beautifully. I look back on those times fondly. These boats aren’t cheap, either. On YachtWorld, asking prices hover between $50k - $100k.
The Accident
A 2023 satellite image of Bridgeview Marina on Lake of the Ozarks, MO.
During the afternoon of May 2nd, 2020, Pajivo was taking on fuel at a Lake of the Ozarks Marina fuel dock on the Lake of the Ozarks, Missouri. Pajivo was reportedly powered by twin Mercruiser engines. Based on similar 1999 Sea Ray 340’s on Yacht World, these were probably twin, big-block (7.4L) Mercruiser engines. These engines use a lot of fuel. Pajivo likely had over 100 gallons of gasoline fuel on board, possibly up to its max capacity of 225 gallons.
An Explosion Occurred…
As reported by police reports, Pajivo suddenly suffered a catastrophic explosion. The explosion was reported to occur at 3:40 PM while restarting the engines after having just taken on fuel. Four people were on board at the time of the explosion: a 47-year-old man, a 37-year-old woman, the driver, a 52-year-old-man, and Shawn Carroll, a 53-year-old-man.
After the explosion occurred, chaos ensued. Various people were either thrown or jumped into the water. The marinas young staff were widely lauded as heroes as they jumped in to save the boaters that had suffered the explosions. Three of the victims received minor to serious injuries and were immediately transported to the hospital after being rescued from the water.
A search ensued for the last victim, Shawn Carroll. At first he was believed to be thrown into the water. Eventually, he was found dead in the engine room of Pajivo. Why was he there? It hasn’t been widely reported as to what Shawn Carroll was doing in the engine room at the time of the explosion, but I’m speculating that he was he was trying to investigate a fuel issue.
Lessons Learned
Boats don’t just explode by themselves. These kinds of explosions are preventable by following some fairly simple precautions.
But first, I think it’s important to understand the nature of the problem. The old-school advice back when we were starting campfires in Vermont was to start the fire with diesel fuel, but NEVER use gasoline. Diesel fuel burns slowly and predictably, while gasoline explodes, burning rapidly and unpredictably. For this reason, catastrophic fuel-related explosions on diesel-powered boats are much more rare than their gasoline powered cousins.
Gasoline fumes are especially explosive, and are what I speculate caused the explosion of Pajivo. Air, when saturated with enough gasoline vapor in an enclosed space, such as in the engine room of a boat that just took on a hundred or so gallons of fuel in the presence of some kind of fuel leak, is a ticking time bomb. All it takes is one spark from absolutely anything in the engine room and the boat will explode.
I’m not going to say that this occurrence is totally common, but I speculate that it happens at least a a dozen or so times a year in the US. It’s common enough that searching “boat explodes” on YouTube will give you tons of hits. Luckily, most of the people I’ve seen in these videos don’t seem to be too seriously hurt, and are, of course, seriously freaked out.
How to Stay Safe
My guess is that, like most of these accidents, this tragedy could have been remedied with some simple inspection and maintenance of the fuel system. The plaintiffs in the court case brought against Sea Ray for event argued that the fuel line had been installed incorrectly to allow for the hose to deteriorate. The plaintiffs lost the case. This boat was over 20 years old at the time of the explosion, and I’ll speculate that it was likely on its original fuel system.
Fuel hose will deteriorate over time, especially in places where it is bent. It’s important to inspect your entire fuel system and be confident that the hoses, fittings, and connections are leak-free and reliable. In salt water environments, brass fuel fittings will corrode. Hose clamps and other pinch fittings that aren’t stainless steel will corrode. Replace them with quality parts. Fuel system parts are definitely not the place to consider going to Wal-Mart or Harbor Freight to save some money for. Use USCG-approved, ethanol-resistant fuel hose, like this: West Marine USCG Approved Fuel Hose (note: this, along with other product links, is an affiliate link that supports our knowledge base). Older boats may be especially prone to deterioration in their fuel hoses due to being built before ethanol was commonly added to gasoline. Use a liquid/gel thread sealant that is rated for fuel connections, like this one. Be sure to check that your fuel tank vent circuit is in good order, as well!
Shut down the electrical system while fueling. Turn battery switches OFF. You don’t want any devices that could produce a spark that could ignite fuel vapors. Clear your passengers off the boat. Now would be a good time for everyone to grab ice creams and sodas at the snack shack.
After fueling, ventilate the boat. After fueling, run your bilge blower for at least four minutes. RTFM (read the effing manual) applies in full force here. The bilge blower is installed in order to evacuate fuel vapors that may build up in the bilge. Be sure that the ducts of your bilge blower are in good order. These will deteriorate in time and need replacement. If your bilge blower goes kaput and needs replacement, be sure to replace the unit with one that is ignition-protected. These units are sealed so that their internal motors will not create sparks that could trigger an explosion. Open hatches below to ventilate fumes that could have built up while fueling. Remember, ventilating will remove any vapors in your bilge, but won’t remove any standing gasoline that may have spilled in the bilge.
Check your bilge with a sniff test after fueling. Open the hatch after fueling and smell for gasoline vapors. Looks for standing gasoline accumulated in the bilge. If you see or smell gasoline, clear off the boat and alert the dock master.
