Lightning is a force of nature that’s both fascinating and terrifying. For yacht owners, it’s not just a dramatic light show flashing through the sky, it’s a real risk that could strike when you least expect it. With lightning hitting Earth more than 8 million times daily, it’s worth understanding how this natural phenomenon can affect your boat, especially in storm-prone areas like Florida, the Gulf of Mexico, and increasingly, the Mediterranean.
When lightning hits your vessel, the consequences can range from electrical chaos to severe structural damage. So, how can you safeguard your floating haven from this unpredictable force of nature? Let’s dive into the impacts of lightning on yachts and explore protective measures that can be used to keep you, your crew, and your vessel safe.
The scary reality of lightning strikes
Yachts today are tech-heavy. From GPS, AIS and autopilot, to radar, MFD’s and satellite communication systems, almost everything is interconnected, and when it comes to lightning that is a vulnerability. A lightning strike can send a surge through this network, potentially damaging or destroying critical sailing and safety systems.
But it doesn’t stop at electronics. Although it’s a much rarer occurrence, there’s the potential for structural damage that can be just as catastrophic. Lightning follows the path of least resistance so when it encounters obstacles like wooden masts or fiberglass hulls it’s possible for the energy to cause cracking, splitting, or even explosions. For vessels with metal hulls, the risk is lower, but the current must still be safely grounded to prevent damage.
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- The sailboat in this photo was safe as the lightning actually struck behind the mast, but the photographer’s sailboat Aurora of London suffered a direct strike weeks later causing damage to their sailing electronics and electrical system.
How lightning can hit
Lightning on open water is no small matter, and its effects depend on whether your boat suffers a direct strike or indirect strike. Understanding how both can impact the yacht is a starting point to finding practical ways to mitigate the chance for damage.
Direct lightning strikes
When lightning hits your yacht it targets the tallest object, usually hitting the mast first. The current can travel down through the boat’s structure, often wreaking havoc on electronic systems. There’s also the potential for it to cause fires, and even damage the hull or keel. The energy seeks the quickest path to water, but if it encounters resistance, it may blast through materials, splitting rudders, damaging wiring or blowing apart fittings.
Indirect lightning strikes
Even if lightning doesn’t strike your vessel directly, the electromagnetic pulse (EMP) generated can still damage your electronics. EMPs create surges in electrical systems frying navigation tools, communication devices, and entertainment equipment. This can happen when lightning hits the water nearby, or even another sailboat in the anchorage.
The fallout from a direct or indirect lightning strike can be severe. There is the potential for a dangerous situation aboard, followed by hefty repair or replacement costs and months of lost cruising time. The good thing is, there are some things you can do to help mitigate the risk of lightning damage.
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- Most modern cruisers rely on their electrical systems and marine electronics to function correctly.
Practical tips for riding out a storm
When a storm looms there are preventative actions you can take to help keep your crew and boat safe. If you spot lightning or hear thunder, follow these measures:
- Seek the safety of a marina or protected cove, avoiding open water where your yacht can become a prime target
- Minimize contact with metal objects like railings and shrouds and keep everyone on board, away from water
- Disconnect shore power, turn off electronics, and remove antenna plugs to help prevent damage from EMPs and voltage surges
- If you have one, ensure your lightning protection system is properly installed and maintained; connective components like sinks, cooktops, and batteries should all be grounded to minimize internal voltage differences
- Place critical electronics inside an EMP shielded case
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- Where would you want to be?
Lightning protection systems
Now here’s the thing; you can’t stop lightning from striking, but you can control what happens when it does. A well designed lightning protection setup can reduce the risk of severe damage to your hull and electronics. These systems aim to control the strike’s impact and direct the current safely into the water.
Lightning conductors
The idea behind a lightning conductor is to direct the path of the current in a way that minimises the severity of the strike’s damage. The basic setup includes lightning rods on the mast, heavy duty copper or steel conductors, and a grounding plate or keel to safely channel the charge into the water. For aluminum and steel yachts, the metal hull acts as a natural conductor. For fiberglass or wooden boats, though, things get trickier. A robust setup is non-negotiable.
High tech lightning protection solutions
When it comes to lightning protection aboard boats there are technically operated protection systems that have been thoroughly tested to prove their efficacy in preventing lightning strikes.
One system is the DDCE marine lightning protection system from Dinnteco. Unlike traditional methods, which aim to manage a strike after it happens, the DDCE works to prevent the strike altogether. It does this by neutralizing the buildup of negative charges in the air, stopping a lightning channel from forming near your boat. Properly installed, this system reduces the chances of a strike dramatically and has gained recognition as an effective lightning deterrent. A downside can be that it’s a pricier option, but still it’s worth considering for those who spend significant time in lightning prone areas or would like the peace of mind.
Another system is the Sertec CMCE Marine, which operates on the same principles as the DDCE. A passive sensor system stabilises the surrounding electrical field in a way that stops the formation of a tracer, reducing the chance of a direct hit.
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- The Sertec CMCE visible at the top of the mast of Travel Sketch’s catamaran, SV Liger
Shielding your electronics
A surge protection system adds another layer of defense against lightning. The purpose of this setup is to keep your navigation gear, lights, and onboard electronics safe from voltage spikes caused by nearby strikes. It’s a bit like wearing a seatbelt – maybe it won’t stop the accident, but it’ll reduce the damage. Installing shielded cable ducts and specialized lightning arresters are two ways you can help ensure your setup can handle the power of a surge.
Protecting your sailboat from lightning
Lightning strikes are unpredictable, but preparation makes all the difference. With the right protection system, you can reduce the risk of catastrophic damage to your yacht and its systems. Investing in surge protection, lightning conductors, and preventative technologies not only safeguards your boat but can also give you peace of mind during storm season.
If you’ve weathered a lightning strike or have tips to share, let us know in the comments. Let’s work together to share information and make the sailing community safer, one boat at a time!
A great article 😁 thank you Michaela.
I did some meta research on this some years ago.
I think it’s important to stress the difference between external lightning protection systems (aka lightning conductors, routing the lightning down to the sea with minimal damages) and lightning prevention systems (doing some magic to prevent the lightning from striking in the first place). When I did my meta research some years ago, the latter hadn’t proven itself useful, I was probably a bit too quick dismissing it as “snake oil”. A very quick meta research now and I conclude that they are probably significantly reducing the probability of getting struck by lightning.
One thing I did learn from my meta-research was that the energy in lightning strikes may differ by orders of magnitude. This may also be related to the fact that lightning strikes often branch out, and also that electronics may be hit by EMP fields even if it isn’t a direct hit. When it comes to lightning conductors, One needs very thick cabling to avoid damage from the worst strikes – and no matter if using conductors or not, it’s very likely that most electronics on board gets fried.
While external lightning protection systems may lower the damages received when being struck by lightning, they may also increase the probability of getting struck by lightning in the first place. Insurance companies does a lot of statistics into those things. I can’t find back to it now, but one insurance company (based in the US) was publishing statistics on lightning-related insurance payouts from boats staying in marinas with and without lightning protection systems, the conclusion was that the lightning protection systems did not make any significant difference.
Some insurance companies are now giving discounts to boats installing lightning prevention systems. This gives an indication that they may be useful.
One thing to note is that a sailing boat is one of the safest places to be during a lightning strike, even if the elevated mast increases the risk of getting struck. The only recorded fatalities comes from people holding a hand on the boom while the mast is struck by lightning.
I have a lightning protection system designed by Dr. Ewen Thomson installed on my FP Saba 50 catamaran. Ewen was a professor of electrical engineering at Uni of Florida (a well known hotspot for lightning). See http://www.marinelightning.com/profile.htm for more details.
We did not get a direct hit rather our friends next to us took the bolt to the mast. They lost all electronics and burned wiring. We lost most electronics just from the EMP. Another boat next to us also lost most electronics from the same bolt. I don’t think a really expensive and questionable lightning preventative system is worth it. There is talk of pros and cons with such a system similar to bonding everything on the boat or not. I am in the not camp on that issue. It sucks getting lightning damage but it is a real possibility when you live on the sea. Electronics are so sensitive that lightning near by can be enough to damage them permanently regardless of having a lightning rod or not.