How To Stop Your Boat From Burning Down

In light of the current boat tragedies that have occurred, plenty of people with petrol powered boats have become curious about how to stay safe out on the water. When we hear about a serious accident on the water, it often leaves people feeling anxious around petrol powered boats, and I believe we need more information about why and how these incidents happen so we can avoid them.

When a vessel is registered, there is no requirement for a safety inspection like you would need to do with your car. Typically, the only time a boat is checked is when the owner attempts to take out an insurance policy, and an insurance survey is requested from the insurer. This means there are plenty of boats out on the water that haven’t been checked in years, and could potentially be a death trap waiting to happen.

I’ve compiled my 9 top tips to avoid a boat explosion.

1. Never interchange automotive parts


Alternators and coils
It’s clear that these alternators and coils are not factory fitted

Often marine parts tend to cost more, and most of the time there is a good reason for this. Automotive parts are not operated in a confined space and there is much less chance of fuel vapours being present (although cars can burn down too). Components such as starter motors, alternators, ignition leads, coils, fuel pumps, and distributor caps are some examples of parts that are marinised and spark arrested for marine use. People will often assume that the the GM block used in many poplar marine engines is the same as automotive, and much cheaper car parts will fit. If the particular component isn’t designed specifically for marine use, do not fit it to your boat.

An example of a part designed exclusively for marine use is a diaphragm fuel pump with return feed. On the automotive alternative, if the fuel pump diaphragm fails it often vents to the atmosphere (in a boats case – the bilge). On a marine engine there is a specific line running from the fuel pump to the carburettor so that if the diaphragm fails, it cycles fuel back into the engine, not into the bilge.

It can be quite confusing as some popular automotive brands also make marine parts, for example Mallory Marine. If in doubt, check with the manufacturer if it’s designed for marine use. Alternatively always using OEM parts is another solution.

Be aware that marine parts don’t last forever. Ignition leads can wear out and short, distributor caps can fail and fuel lines can crack and perish. Although in some cases these older boats aren’t worth much money, it’s not worth putting your family and fellow boaters at risk by not carrying out repairs the engine needs.

2. Inspect your bilge blower/s

Damaged blower hose
This blower hose was completely ripped meaning air would be cycling around, and not out of the bilge

I don’t know how many times I’ve inspected boats where the blower has been disconnected, damaged or completely removed. It’s quite common that the blower hose rips, causing the whole system to be completely ineffective. If you have a ripped blower hose, when you switch your blower on you’re not assisting with removing any possible fuel vapours. The cost of a marine blower and suitable hose is cheap, and running the blower for a minimum of 5 minutes is essential for any petrol powered boat.

Further to this, lifting your engine hatch to allow it to air out can also aid in reducing the likelihood of any explosion.

3. Run your blower for 5 minutes

If you don’t know where the blower is, whether you should have one, or how to operate it, you need to find out. Boats fitted with outboard motors will not have a blower, as the engine is bolted to the back of the boat and is not actually inside the boat. This does not mean you can’t have an outboard catch on fire. If you have an outboard, be sure to check for any oil slicks in the water below the engine, which may indicate a fuel leak that’s dripping down into the water.

3. Check where you are fueling up

Over the years I’ve heard of people putting 100’s of litres of fuel in their rod holder, only to find out later on. This is a sure recipe for a flame thrower, and although in one case it was diesel, you’d want to be sure you don’t do it with petrol.

4. Be extra careful when fueling up

Most of the recent incidents happened shortly after fuelling up. If you are fueling up, be sure to check your engine room before starting the engines. If you remove the hatch and can smell fuel, you need to find out where and why. Do not attempt to start engines with any fuel smell present.

5. Check your fuel lines

cracked fuel line
A 21 year old fuel line beginning to show its age

If there are any signs of cracking or deterioration, it’s a sign you need to replace your fuel lines. If you do not know how old your fuel lines are, it’s a good idea to replace them as a precautionary measure.

6. Check your fuel filters

CAV style filters are more likely to leak when assembled incorrectly as they have more seals. A spin on style filter has less chance, although may not provide a fuel sight glass. Sight bowls are acceptable, but it increases the possibility of a fuel leak.

CAV fuel filter
CAV fuel filter with 4 seals
Spin on fuel filter
Spin on fuel filter with 1 seal

7. Inspect your fuel tank

Depending on the age of the boat, it is possible for fuel tanks to fracture or fail. It is also important you inspect all fittings going into the fuel tank, such as fuel pickups and fillers.

8. Check your fuel breather/s

Fuel tank breathers can become clogged or damaged, and no longer serve their purpose. If this has happened, you’re more likely to have an issue with fuel getting into a confined space. For example, if a fuel breather snapped off the side of the hull, it may be venting internally. When you’re fueling up your boat, you may not know when the tank is full and it could be filling your bilges.

9. Do not store fuel in jerry cans on the vessel

Fuel should be stored in the fuel tank with appropriate venting.

What about diesel?

Whilst it is true that diesel has very little risk of explosion, a well kept petrol boat with adequate maintenance should not be a hazard. A diesel will incur higher maintenance and replacement costs, and a petrol is still a good viable option for smaller boats (typically under 35ft).

How about electrical fires?

Whilst this is not an exhaustive list, there are a multitude of reasons a boat can catch on fire – electrical being one of them. Generally speaking electrical fires are caused by incorrectly wired systems done by home-enthusiasts or DIY’ers. All wiring on a boat should be done by a suitably qualified marine electrician, and if in doubt you should enquire with one to check out a suspect system.

If you are unsure whether your boat is safe, do not hesitate to reach out to a suitable qualified marine mechanic, surveyor or repair facility. Most of the items on this list are easily spotted by an experienced professional.

Explore More

articles | January 15, 2022

Things You Need To Consider When Buying A Boat

“Would you buy this boat?” is the million (or multi-million) dollar question we get asked on a daily basis when someone is buying a boat. Unfortunately, we cannot provide a simple yes or no answer. Just like people, boats are diverse, complicated and sometimes carry a lot of baggage (some...

articles | November 14, 2021

Watermakers and Potable Water on Private Yachts

Potable water, also known as drinking water is something you may be interested in if you find yourself on a boat for a long period of time. We often get asked about how to use water makers onboard and how good the quality of water is, and in this article...
boat engine bay with volvo its

articles | August 23, 2021

The 3 Different Types Of Boat Maintenance

What are the difference types of maintenance that can be applied to engines and equipment on boats? Anything over the 40ft mark will often have a number of engines, generator/s and other serviceable items onboard (think water makers, stabilisers) that will need regular maintenance. I would say that we could...