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Through Fire and Water – Investigating Marine Fire and Explosion Claims

March 3, 2022

In any forensic investigation, the first step is determining the origin of the incident. Finding the origin and cause of a fire requires working from the least damage to the most tremendous damage. It means completing an exterior examination before an interior examination in marine fire investigations

There is no trend on the “extent of damage in marine investigations.” For example, a boat could remain intact after a fire. However, it could also suffer a total loss, more typical of a marine fire. 

Information to consider in marine fire investigations:

  1. Time and place – Whether the boat is in a marina or an isolated area will determine the scope of the investigation, as will the time of day. It is equally crucial to consider if the loss occurred at the beginning or end of the boating season. Some owners try to get rid of their boats at the start of the season to buy a new one. The end of the season also increases the likelihood of arson. Extensive repairs are often necessary. Therefore, other owners attempt insurance fraud to avoid repairing or selling their boats. 
  2. Physical evidence – When investigating marine claims, it is crucial to look for char patterns from the photographs provided. Examine any wooden components found in the boat. Fiberglass delamination also requires extensive consideration. It is the epoxy resin that burns with fiberglass, not the fiberglass mat. Therefore, the number of delaminated fiberglass layers indicates how long the fire burned. Other areas that require consideration are heat patterns, discoloration or melting of metals, and melting of plastics. These are all indicators of proximity to and direction of the fire.

The most common causes of fires

Causes of fire can be classified into two main categories – accidental fire and arson. 

Accidental fires

1.1. Fuel-related: These fires have varying degrees, owing to their multiple possible sources – gasoline, diesel, propane, alcohol, and engine oil. 

1.2. Electrical-related: Boats typically have one of two electrical sources – 12 V DC (the onboard electrical batteries) or 120 V AC. The latter is usually found when boats have shore power, but some have onboard generators that produce 120 V currents. 

1.3. Other causes: Some fires are caused by the spontaneous combustion of rags soaked with teak oil or fiberglass lamination. Fiberglass lamination generates heat and can cause a fire if done improperly. Smoking materials and maintenance activities like welding and grinding can also lead to boat fires. 


Case study 1: Electrical fire

A 30-foot express sailboat caught fire while in a Toronto marina. The owner of this boat lived on it but was at work during the incident. 

Figure 1: The 30 ft. express sailboat after the fire.

The boat’s exterior did not sustain much damage, and the fire was self-extinguished. The cabin area primarily incurred smoke damage during the fire. There was minor heat damage in the area. There was no evidence of fire on the aft deck area either. 

Figure 2: A close-up of the hatch area.

Heat defamation and smoke damage were observed on the hatch, indicating that the fire had migrated into the area. The metal part shown in figure 2 is a junction box that may not be appropriate for a boat. 

Figure 3: Interior fire damage in the aft.

The boat’s interior near the hatch showed more extensive damage than other areas. The battery switch – the orange dial – switched between two batteries. It sustained some fire damage, but the more significant damage was to the breaker panel. 

Figure 4: The battery switch.

Figure 4 shows significant exposure and fire damage to the back and front of the battery switch. However, there was no evidence of internal failure. The back of the battery switch also shows the junction box, which was a receptacle. Upon further inspection of the upper half of the receptacle, we noted that the owner placed a regular 14-gauge NMD electrical cable into the plug. The bottom half had suffered minor fire damage and had a standard electrical cord. 

Figure 5: The open junction box.

We opened the receptacle, after which we discovered that the upper half was not severely damaged. However, part of the lower half had disintegrated, revealing the interior copper material. The left-hand side of the receptacle showed that it was the center of the electrical activity in this case.

Figure 6: The bottom half of the receptacle.

The bottom plug melted off the junction box. The other half that did not melt had green oxide. Because the junction box was designed for a house, it was not watertight or moisture resistant. As boats are not entirely watertight on the exterior, water infiltrated into the receptacle box. It built up corrosion, which then became conductive. It caused an electrical failure, resulting in a fire. 

Key lessons

  • Boat owners commonly make their modifications to avoid labor costs. 
  • They do not always use the proper materials. 
  • As an adjuster, it is crucial to preserve the evidence at the scene. 
  • Ask probing questions during the investigation

Questions to ask as an adjuster

  1. Have there been any repairs or modifications done to the boat lately? 
  2. If so, who did the modifications? 

Regardless of who did the work, obtain detailed statements to protect yourself from liability. It is crucial to ensure that these points are covered if going to litigation. 

Case study 2: Electrical fire II

A 1999 47-foot Catalina yacht caught fire while onshore. The owner of the boat had it winterized. As a result, the boat did not sustain exterior fire damage. However, when the boat owner went to get the boat ready in the spring, he discovered that there had been a fire because everything was closed, the fire self-extinguished. 

The yacht was in an exposed area, subject to winds and harsh weather during winter. It was a critical factor in this loss. The aft deck area sustained very minimal damage. However, the plastic used to seal the hatch cover melted, and there was extensive soot around the opening for the hatch (figure 7). 

Figure 7: The hatch area after the fire.

A lot of soot and carbon deposits were observed inside the cabin area. Heat damage was also observed in the ceiling of the cabin. 

Figure 8: Inside the cabin area.

The ceiling, plastic, and fiberglass in the cabin were subjected to thermal degradation and were beginning to crumble. In addition, the plastic inside the boat was melting, indicating high levels of heat. The floor, however, showed a decrease in heat damage. In addition, there was charring on the boat’s navigation table, which indicates that this is where the fire originated. 

Figure 9: Damaged equipment in the area of origin.

All the electrical equipment was concentrated in the area shown in figure 9. The fire damage extended to the base of the seat and then progressed upward. 

Figure 10: The lower section of the damaged area.

The orange color in the burnt equipment is an indication that the item was the battery contact switch. The little piece of wood marked in figure 11 has a melted plastic cover. 

Figure 11: A close-up of the charred wooden piece.

Deep charring was observed inside the piece of wood, clearly indicating that the fire originated within that area. For clearer visualization of the electrical wiring, we removed the cover. 

The battery cables had green oxide residue, which was not from water in this case. Instead, the green oxide appeared because the copper wiring was built up with heat and then oxidized. 

Figure 12: The oxidized cables.

The oxidation appeared to have been occurring over time in the boat. However, the exact duration was unknown because we did not know when the fire occurred. The heavy cable and other smaller wires were severed. The cables would be going to various parts of the boat for the 12 V DC electrical system.

Figure 13: One of the severed battery cables.

The part on the left (figure 13) is the end that would have been at the battery switch. Unfortunately, the wire had also been severed. As the boat was onshore, there was no need for electrical power. However, more than two large global batteries were found upon inspection of the hatch covers in the galley kitchen area. 

Figure 14: The connected batteries in the gallery area.

The boat owner left these batteries connected, meaning the boat always had live 12 V power, even when on dry land in the middle of winter. And there was no need for this boat to have electrical power. 

Figure 15: An exterior shot of the boat, with an arrow pointing to the mast.

As shown in figure 15, the boat’s mast was in place. It sat on top of the roof cabin and did not go down. During winter, the mast could have been subjected to excessively high winds. It would shake and the vibration transferred through the boat. The wires would be jerked around. As a result, they were rubbing together for some time. The wires then shorted out, leading to a fire. 

Key lesson

  • There is no need to keep batteries and other electrical sources connected to the vessel’s electrical system when the boat is in storage.

Questions to ask in fire claims involving a boat in storage

  1. Was the boat winterized? 
  2. If so, who did the work? Many boat owners winterize the boat themselves to save money. If they did the job themselves, have them explain what they did for the winterizing. 
  3. Were the batteries disconnected?
  4. Could the mast have been taken down?

Case study 3: Fuel explosion

In 1986 a 25-foot Doral Citation had an explosion after refueling. The owners had recently purchased the boat, and it had no apparent problems. After refueling the boat, they went to start the engines. The boat had an explosion. It is not known whether they ran the bilge fans long enough to evacuate any gasoline vapors, which they were supposed to. The boat was intact after the explosion. 

Figure 16: The location where the explosion occurred.

In figure 16, the fuel pump is in position, and the red frame shows that the glass of the fuel pump was cracked from the force of the explosion. The hull was separated from the upper deck area, and glasses had broken on one side of the boat. Fortunately, nobody was hurt in this incident. 

The engine compartment showed no evidence of damage inside. However, the surrounding items sustained damage (figure 17). 

Figure 17: The engine compartment.

The railings were broken off and separated. The console was displaced to a point where it blocked the porthole window. These damages were an indication of the push that took place. The engine compartment sustained minimal heat damage. The plastic that covered the spiral wire on the right-hand side of the compartment had melted off, but there was no obvious sign of fire within the area. However, the ignition source could be traced to the engine compartment.

The railing was lifted upwards, cracked, and torn. The explosion also blew into the cabin and displaced the steps. We also observed a lot of displacement and delamination of plastic due to the flexing of the hull (figure 18). 

Figure 18: The exposed fuel line.

The red hose is the fuel line, and it had masking tape near the fitting. There was a clamp on the fitting, meaning the fuel line was firmly secured. We believe the masking tape was used as a seal by the previous boat owners. 

Figure 19: The vent line for the fuel tank.

Next to the fitting is the vent line for the fuel tank. When filling up the fuel tank, gasoline vapors and air get pushed down to the fuel tank. To avoid bringing these vapors into the engine compartment, there is a line that drags those vapors and purges them on the boat’s exterior. The vent line was a black rubber hose with no hose clamp in this case. It also had no masking tape holding it in place. As such, when the boat was refueled, those vapors accumulated in the engine compartment instead of being vented to the boat’s exterior. 

Key lesson

  • Purchasing a used boat has risks, and so does insuring it.

Questions to ask on every file

  1. Where and when did you buy the boat? 
  2. Was it previously owned? 
  3. If so, did you have a marine surveyor examine the vessel? A marine surveyor conducts a thorough inspection of the boat and gives the buyer an assessment of its condition. 
  4. Was there any recent or past service work done on the boat?
  5. If so, who did the work? 

Case study 4: Careless workmanship

The owners of a 2001 Carver 350 were sailing the boat across Georgian Bay from Killarney, Ontario, to Manitoulin Island. En route, they lost power in one of the engines and limped to Manitoulin Island with one engine. They pulled into a service area marine mechanic, but they did not have room to hold the boat. The boat was then taken to a public marina owned by the municipality, and the mechanics came to the boat. As the mechanics began working on it, a fireball suddenly went through the boat. Fortunately, the occupants sustained no injuries. The boat was destroyed. 

Figure 20: How we found the boat.

The municipality kept water pumps going on the boat to prevent sinking. But, unfortunately, they had to stop, and the boat sank. We retained commercial divers and used airbags and pumps to get the boat back to a floating condition. 

Figure 21: The forward area of the boat.

The boat sustained extensive damage. There was fire damage on the hull, and no cabin superstructure was left, consistent with a fireball moving through the boat. The boat’s two engines had a varying extent of the damage. 

Figure 22: The engines.

The starboard engine fuel tank was relatively undamaged, and the carburetor and filter were still in place. Fuel lines and coolant lines were also not too damaged. The port engine fuel tank was partially melted. We observed extensive damage to the top of the engine, and the carburetor was wholly gone. 

Figure 23: A closer view of the severely damaged port engine.

The port engine was fuel-injected, meaning the fuel rail runs on both sides. Pressurized gasoline is distributed in the fuel rail and then injected into the cylinders when required. The fuel rails had a Schrader valve, which is used to bleed air out when the system is set up, or work is being done on it. We noticed a foreign object on the Schrader valve of the port engine, which we then closely inspected. 

Figure 24: The port engine Schrader valve, still attached to the fuel rail.

We discovered that a pressure gauge was connected to the Schrader valve. The mechanics working on the boat had hooked up the pressure gauge to the fuel rail to figure out what caused the engine to run improperly. 

The mechanics left the pressure gauge on top of the engine. A pressure gauge has long plastic tubing meant for bleeding air off the line and ensuring that gasoline is coming out. We concluded that the plastic tubing fell off the engine, got tangled up in the pulleys while the engine was running, and ripped off. As a result, high-pressure gasoline was dumped into the engine compartment, which was ignited and caused a flash fire. 

Key lessons

  • Faulty workmanship, improper installations, improper choice of materials used in installations, or improper choice of equipment used in repairs are standard. No regulatory bodies are providing formal training programs or licensing for marine mechanics. They are simply mechanics specializing in boats based on their exposure and experience. Therefore, the quality of workmanship and the repairs done on boats is dependent on the quality of informal training and the experience of the mechanic working on the boat.
  • Ensure that you get sufficient information about the service and the mechanics who did the work when investigating a claim. 

Questions to ask on every file

  1. What is the name of the company that did the repairs? Include the mechanic’s information.
  2. What components were repaired or replaced, and from where?
  3. Were the parts suitable for the marine application? It is common for boat owners to use a car alternator on a marine engine. But unlike car alternators, marine alternators are designed for wet environments. 

Case study 5: Human error

A boat owner was preparing it for winterization when a flash fire occurred. He subsequently inhaled hot gases and later died. The incident resulted in a lawsuit against various parties. The boat exterior had minimal damage after the incident; there was only a bit of soot around. The cabin had no apparent fire damage either. The engine compartment beneath the cabin also had no significant fire damage, with only a bit of soot visible. The plastic over the hatch cover melted, indicating heat in the area, but not enough to ignite the plastic. 

Figure 25: The engine compartment.

Further inspection of the engine compartment revealed that work was being done. In addition, one of the battery cables had been disconnected, indicating that the owner was working on the batteries. 

Figure 26: The engine compartment, with the cup inside.

A cup was found in the engine compartment. The engine compartment upper area did not have extensive fire damage, but the plastic on the built fan vents had melted off the hoses. An aerosol can of multi-purpose lubricant was recovered from the scene. It was proven to be the source of the incident. 

Figure 27: The aerosol can.

The can was not severely damaged, but the cover had melted. This product was a WD-40 spinoff sold by a large department store. The mark indicated by the arrow in figure 28 is a hole burned through the sidewall of the can. The can label was made of plastic, but it did not cover the seam, leaving the seam as the only exposed metal other than the base. 

Figure 28: The base of the can.

Another mark on the base is lined up with the one on the seam (figure 29). This product used butane – a flammable gas – as a fuel. If you burn a hole through the sidewall of the can, butane gas comes out very quickly. In the presence of an ignition source, it causes a fire. 

We measured the distance from the seam mark to the base of the can (5.25 In) and the distance between the terminal posts on the battery (5.25 In). We, therefore, concluded that the aerosol fell, and the unprotected metal made contact with the batteries, resulting in an electrical short that burned a hole in the can. As the can roll off, a spark from the electrical short ignited the butane gas, leading to the incident. 

Key lessons

  • Humans make mistakes, and some have more dire consequences than others. In this case, the mistake was fatal.
  • The nature of boats, having confined areas sometimes makes it difficult to do the simplest tasks. 
  • Therefore, human error claims such as these are common.

Questions to ask as an adjuster or lawyer

  1. Focus on the insured, their actions, background, and experience. We often run into claims where the insured is a contractor or mechanic and wants to do the work themselves. Some people think their technical background is transferable to a marine environment. If you have that in a statement, it helps bring context to the story. 
  2. Ask if they purchased any products and where they purchased them. If they have receipts, get them because there may be a product liability claim. 

Case study 6: Manufacturing defect

An owner purchased a boat built in China through a sales agent. The owner had only stepped onboard once and never operated it when the incident occurred. After additional work was done in the United States, the boat was being sailed across Lake Ontario by the sales agent and his captain. A fire suppression system was installed in the US, and the hull was repainted and other modifications. As the sales agent and captain landed at the underwater boat show in Toronto, they saw fire. 

Figure 29: Inside the cabin.

There was minimal exterior damage to the boat. However, there was damage in the cabin. The fire had migrated up from the area from below into the cabin. This indicated that the fire occurred in the engine. 

Figure 30: The two large diesel engines.

One of the two access points into the engine compartment had significant fire damage. The engine compartment had two large diesel engines. The diesel engine on the right-hand side of the photograph sustained more fire damage than the one on the left. Extensive fire damage was also observed in the area where the battery switches were located. 

Figure 31: The fire suppression system.

The fire suppression system installed at a marina in the US suffered extensive fire damage. This system should have automatically set the fire before it reached this stage, but it did not. 

Figure 32: The fire extinguisher.

The red circle in figure 32 shows where the manual cable hooks up to a glass bulb. If you pull a handle, you can break the bulb. The bulb is filled with liquid and breaks when exposed to fire, causing the fire suppression system to discharge automatically. The gauge was destroyed, and we confirmed that the cylinder was empty at some point. 

Figure 33: The top part of the fire extinguisher.

The glass bulb, in this case, was not broken. When we looked at the fire suppression system more closely with the manufacturer, the bulb did not have any issues. However, we noticed that the glass was cracked when we touched it. 

Figure 34: The bulb with a cracked glass.

It had probably been cracked when installed, and the liquid inside leaked out. The liquid could have seeped out as the heat built up, but it did not break the bulb. Thus, the system did not fire because without the glass in place; it could not open the valve. 

When they discovered the fire, the captain of the boat pulled the manual firing mechanism in the helm. However, that had no effect. 

Figure 35: The manual firing mechanism.

We discovered that when they installed the manual firing mechanism, the marina drilled a hole to fit and slide the whole thing instead of drilling a hole no bigger than the threaded bushing. The hole would ensure that the bolt and washer were locked in place when correctly sized. And so, when pulling on the handle, the wire would move, not the whole assembly. We, therefore, concluded that a manufacturer’s defect led to an electrical fire in the boat. 

Key lessons

  • Not all foreign manufactured boats are built to North American standards. Research the organization to which they belong. We found several other boats in the United States by the same manufacturer. And they all had electrical fires in different locations. It was determined that the wiring was not done correctly. The Chinese manufacturer and the US marina were sued as a result. 
  • If you have been indicated as an interested party, retain an expert right away. The US marina provided incorrect evidence and paid 75% of the costs incurred in the loss.
  • Obtain all purchasing documentation. 

Questions to ask

  1. Where was the boat purchased? 
  2. Was any work done after delivery?
  3. If so, who did the work?

Case study 7: Arson

1992, 24-foot Sea Ray was in winter storage in a compound. The owner had been on board that day to check on it, and a fire was discovered shortly after he left—the fire self-extinguished. As shown in figure 37, the fire came from the cabin. The engine compartment was intact, and the batteries were connected for no reason. Since there was no fire in the engine compartment, we investigated the cabin, which sustained moderate heat damage. 

Figure 36: The cabin interior.

The effects of the heat were visible in the delaminated plastic on the cabin ceiling. In addition, the seat and bed cushions were all burnt from the bottom. 

Figure 37: The seat of the fire.

Our examination recovered a plastic bottle with a wick inside. The plastic bottle contained a flammable liquid, and it was used to initiate the fire. 

Key lessons

  • It is essential to know when and where the loss took place.
  • The time of year should also be taken into consideration during an investigation.
  • One must know the activities of the insured before the fire. 

Team up with Origin and Cause for Marine Fire and Explosion Claims

Origin and Cause has a team of extremely professional and trained investigators and forensic engineers who get to the root cause of fires and explosions. We specialize in marine fires and can help uncover the true cause by following scientific procedures and methods to arrive at factual conclusions. Get accurate answers and information that can be upheld in a court of law. Contact Origin and Cause at 1-888-624-3473 today to submit your case!