The single best way to protect your portable boat electronics from a lightning strike is to put them in your oven or microwave before the storm hits. In 17 years of living aboard — including seasons in the Sea of Cortez and a full rainy season anchored in El Salvador — I watched other boats get hit. Time after time, the electronics they’d stowed in the oven came through fine. The ones left out did not.
Here’s why it works, what to put in, and what won’t protect you.
Why the Oven Works
Your oven (and microwave) acts as a Faraday cage — a solid metal enclosure that causes electrical energy to flow around the outside rather than through the interior. When lightning strikes near your boat, the electromagnetic pulse travels across the metal surfaces and dissipates without reaching anything inside.
This is basic physics, and it holds up in practice. The night the photo above was taken, a boat within 100 yards of us in our El Salvador anchorage took a direct strike. Everything hard-wired on that boat was gone. The electronics they’d put in their oven were fine.
We heard that same story from cruisers again and again over the years.
What to Put in the Oven
Any time we saw a storm building, or when we went to bed in lightning country, we’d load up the oven and microwave with:
- Handheld GPS
- Handheld VHF
- Cell phone
- Laptop, card readers, and cables to connect to the handheld GPS
- Tablet with navigation app
- Digital camera
- Chargers, spare batteries, and data cards for all of the above
If we’d had a handheld depth sounder, it would have gone in too.
This won’t save your chartplotter, your VHF radio at the nav station, or your autopilot. Those are wired into the boat and a direct strike will almost certainly take them out. But you’ll have enough to navigate safely and communicate — and that’s what matters when you’re in a remote anchorage with no marine electronics store for 300 miles.
An Important Warning
Never light the oven while your electronics are inside.
For us this was never a risk — our oven igniter was broken and I had to light it manually, so there was no way to accidentally fire it up. But if yours lights with the push of a button, put a piece of tape over it with “ELECTRONICS INSIDE” written on it. One distracted moment is all it takes to melt everything you were trying to protect.
What About Faraday Bags?
Some cruisers have suggested using Faraday bags as an alternative if your boat doesn’t have an oven or microwave.
It’s worth knowing what you’re actually getting. Most Faraday bags sold on Amazon are designed for RFID blocking — protecting credit cards and passports from digital skimming. They are not designed for lightning protection and won’t do anything meaningful in an EMP event.
There is a separate category of purpose-built EMP Faraday bags, tested to military standards, that are designed for electromagnetic pulse protection. These may offer some protection, but even the best ones have seams, closures, and folded openings — all potential weak points when you’re dealing with the enormous energy of a nearby lightning strike. A solid metal box with no gaps is a fundamentally different level of protection.
If you don’t have an oven or microwave, a metal trash can with a tight-fitting metal lid is a reasonable substitute. Mark suggests that option, and it makes sense — no seams, no closures that can fail, just metal on all sides.
Other Things Worth Protecting
Cruisers Chris and Janet reminded me that items with RFID chips — credit cards and passports — can have the chip damaged by a lightning strike’s electromagnetic pulse with no visible sign of damage. Worth throwing those in the oven too.
And anything you can’t fit in a Faraday enclosure should at the very least be unplugged. It won’t protect the equipment from a direct strike, but it removes one path for the energy to travel through.
Prep Before the Storm, Not During It
The time to stow your electronics is when you see the storm coming, not when it’s on top of you. If you’re anchored in a lightning-prone area — Florida, the Bahamas, Central America, anywhere with regular afternoon thunderstorms — make it part of your standard pre-storm routine.
For the full checklist of what to do when a squall is headed your way, see my guide to dealing with squalls at anchor.
Know What’s Coming Before It Arrives
Protecting your electronics is the reactive part. The proactive part is learning to read the forecast well enough that a squall doesn’t catch you off guard.
Ready to Read the Weather Like a Cruiser?
My book Weather Basics for Boaters: The Details That Matter doesn’t try to make you a meteorologist. It shows you exactly what to look for in the apps you already use — wind, gusts, waves, current, squalls — and how to spot the details that tell you what the day will actually bring on the water.
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Carolyn Shearlock has lived aboard full-time for 17 years, splitting her time between a Tayana 37 monohull and a Gemini 105 catamaran. She’s cruised over 14,000 miles, from Pacific Mexico and Central America to Florida and the Bahamas, gaining firsthand experience with the joys and challenges of life on the water.
Through The Boat Galley, Carolyn has helped thousands of people explore, prepare for, and enjoy life afloat. She shares her expertise as an instructor at Cruisers University, in leading boating publications, and through her bestselling book, The Boat Galley Cookbook. She is passionate about helping others embark on their liveaboard journey—making life on the water simpler, safer, and more enjoyable.
The Boat Galley says
Ouch!
Carolyn Shearlock says
Hmm, I hadn’t heard that. I’m going to bet that most oven doors do have a glass window and know of several that have apparently protected the electronics inside (things that weren’t in the oven were damaged), so it may give some protection, depending on how the lightning travels.
Thanks for adding that!
Deanne says
Love the boat galley website and cookbook, by the way. We have cruised Mexico for the past year and are getting ready to do the puddle jump, and if I could only keep one cookbook it would be yours. Thanks!
Carolyn Shearlock says
Wow! Thanks!
The Boat Galley says
My understanding is that it will not, unless there’s a metal mesh in the glass (like what’s in a microwave window).
Melissa says
I’m not certain that the window would cause a real issue. Cars are effective faraday cages even with windows, as long as the frame is mostly made of metal and not fiber glass. I also remember visiting a science museum at least 15 years ago where they had a faraday cage set up that you could sit in. It looked like a bird cage, but there were no windows or mesh in the open areas (that I can recall at least!). The people working there informed us that as long as you did not touch the outside of the metal when lightening strikes a car, you won’t get hurt. Maybe the window in the oven door isn’t ideal, but I don’t think it would completely compromise the use of the oven as a faraday cage.
Mark Zalenski says
…with a lid of course
Carolyn Shearlock says
All I can say is that boats that were struck by lightning and had small items in the oven — those items weren’t damaged when many (but not all) other electronics on board were. I tend to think the oven offered protection, but nothing can be guaranteed.
The Boat Galley says
Not personally, but two boats anchored near us in El Salvador.
Beth Burlingame says
Thanks! I almost never use my oven, so it is a good place. I’m considering putting a small safe on the boat and with its metal construction, it should also work as a faraday cage.
Marc Dacey says
You can make a Faraday cage out of cardboard and foil. The key is that the foil must be continuously connected. Unfortunately, a lot of good advice on this is found on paranoid “prepper” sites from people who have the cold sweats over the reptiles in government taking their guns.
The Boat Galley says
Yeach. Unfortunately we can’t put the “big stuff” in the oven . . .
Stuart Dutton says
I wonder if this actually works or if it is an assumption that it works? I wonder if there have been any studies or experiments done. I guess it couldn’t hurt regardless.
The Boat Galley says
I would never laugh . . .
Meredith Wright says
Always better safe than sorry!
Alison Stroebel says
The Boat Galley 😂😂😂😂😂😜😜🍷🍷🍻
Alison Stroebel says
The Boat Galley 😂😂😂😂🍻🍷😜
Sherry Matas says
We were struck almost exactly one year ago… All of the hard wired electronics, including the voltage control regulator in the generator, inverter, refrigeration, nav lights, DC panel, house bank ect all fried. We were onboard, so we did the logical thing for a lightning storm and unplugged the small portable electronics. They were all fine.
I had the tv on the local weather report. Power strip did its job, tv is fine. The old laptop that we wanted to die was plugged in to a gfi outlet, unfortunately it’s still a live and kicking.
Important thing is to read your insurance policy. We changed companies this year, so I’ve been reading a lot of policies. I found a lot of exclusions for portable electronics and computers regardless of how it was damaged.
The Boat Galley says
Stuart Dutton I know people who were struck by lightning and the things in the oven were the only electronics that survived.
Meredith Wright says
Sherry Matas Good info on the insurance…
The Boat Galley says
Yes, the electrical charge passes around the outside of the Farraday cage and items inside are not affected. The article explains it in more detail.
Carolyn Shearlock says
I can so see that happening. Glad you didn’t turn the oven on, thinking everything was out!
Craig Simmons says
Thank you, Carolyn Shearlock, you are an awesome writer.