As the almost-daily thunderstorms moved in over our anchorage in Bahia del Sol, El Salvador, we prepped the boat, securing the dinghy motor to the rail and hoisting the dinghy, closing the hatches and ports, taking down the laundry, wind scoop and US flag, checking the anchor and snubbers . . . and throwing all the electronics that would fit into the oven and microwave. Huh??
The impetus for this article was an essay on the last page of the April 2012 SAIL magazine, titled “When You See the Southern Cross.” Towards the end of the essay, there’s just a couple of sentences devoted to sustaining a direct lightning strike, “losing practically every electrical instrument onboard” and the “effort it took to return our crippled craft to base . . . “
Imagine being in a secluded anchorage and losing every piece of electronic gear. YIKES! But I do have some good news, and it involves your oven (and microwave, if you have one).
Dave and I come from the Midwest and thought we’d seen some pretty wicked thunderstorms living there. Then we experienced some chubascos in the Sea of Cortez and then the fierce nightly thunderstorms in El Salvador’s rainy season. And while we never had a direct lightning strike, other boats in our anchorage weren’t so lucky. The night that the photo at right was taken, a boat within 100 yards of us was hit.
How to Protect Your Electronics
Various cruisers devised all sorts of grounding systems but frankly, none seemed to protect the boats that were hit. All lost some to all of their electronics (luckily, none had holes blown in the hull).
The good news was that time after time, anything they’d put in their oven or microwave was okay. I’ll keep the explanation simple, primarily because I’m not enough of a physicist to fully understand it. Basically the oven/microwave acts as a Farraday cage — or a full metal box — and when lightning hits it, just flows over the outside without disturbing anything inside.
What to Put in the Oven
So, any time we’d see a storm approaching — or when we went to bed when we were in “lightning country” — we’d put the following in the oven and microwave:
- Handheld GPS
- Handheld VHF
- Cell phone
- Laptop and card readers and cables to connect to handheld GPS
- Tablets with navigation program (AquaMap)
- Digital camera
- Chargers, spare batteries and data cards for all the above
If we had a handheld depth sounder, we would have added it, too.
If you do get a direct strike, you won’t have all your normal goodies to get home. And unfortunately, this won’t protect the really expensive stuff. But you’ll have enough to safely navigate and communicate.
Warning
Just be careful that you never light the oven with all your electronic goodies in there. For us, that wasn’t a problem as the igniter didn’t work and I had to open the oven and manually light it. But if you can light yours with just a button, you might want to put a piece of tape over the button with “Electronics!” written on it so that no one inadvertently melts them.
Bottom Line
Let’s hope you never have a direct lightning strike — but if you do, ensure that your basic electronics are adequately protected. Like anything else with boating, if you get in the habit of doing it every time there’s lightning, you’ll never be saying “if only . . . “
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Joyce Campbell says
again thank you from now on I will use the oven more then just for cooking again thank you
Debbie Weiss Luitweiler on Facebook says
Have used the oven for that on many occasions during our frequent Florida storms.
Candy Ann Williams on Facebook says
Thanks for sharing…I will remember this when we get to Fla. and all of their storms.
Dawn says
That’s some great advice especially since we are heading up into the Sea of Cortez this summer!!
John Huft on Facebook says
Check before you preheat for those brownies! 😉
The Boat Galley on Facebook says
Not a problem if your automatic lighter doesn’t work . . . you HAVE to open the oven to light it!
Chris&Janet says
You might also want to put anything that contains an RFID chip in there as well. The electromagnetic pulse that comes with lightning can destroy the chip’s functionality without leaving any signs. Two things come immediately to mind. Passports and some credit cards.
Carolyn Shearlock says
Good idea!
The Boat Galley says
Oh no! So sorry to hear that! Hope you didn’t have too much damage.
Melissa Watkins Alexander says
My husband and I are Computer People. Bare minimum, we’re planning to build a Faraday cage in one of the extra cabins so we can store computers there all the time we’re not actively using them. He’ll likely explore ways to create a Faraday cage around all the electronics (though it may not be possible, if only because of antennaes).
Jan Alexander says
FWIW, I recently met someone whose boat took a direct lightning hit. Computers and cell phones were not in oven or protected in any way and they were all fine.
Lacy King says
Me too 3 weeks ago got hit in Phuket. Cell phones batteries BMS and inverter ok. All other electronics fried
The Boat Galley says
Sometimes they are, and sometimes it takes a while for all the problems to show up. I worked in an office that took a lightning strike. Some things seemed fine and six months later had problems that were diagnosed as being caused by the lightning.
Sebago Seymour says
We learned that after we got hit by lightning this past Thanksgiving in Boot Key Harbor. Love your book! http://svmiamante.wordpress.com
Sebago Seymour says
Thousands but no one was hurt.
Sebago Seymour says
Anything with a wire was effected.
The Boat Galley says
Ouch!
Deanne says
My understanding is if your oven has a glass door (like ours) then it is not a Farraday cage and would not protect your electronics. However, microwaves have a metal screen in the door that should do the trick. You can also buy Farraday cage bags (or keep the ones electronics usually come packaged in), but wrapping stuff in aluminum foil works too.
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!
S/V Dos Libras says
Our oven has a glass window… do you think it’ll still work with a break in the metal box?
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.
Lynn Kaak says
Sounds good in theory, but the connection by the door may not be good enough to make a good ferridite shield. But it can’t hurt to try.
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.
Mark Zalenski says
A small metal trash can also makes a good Faraday cage, which is the proper name for an emf shielding enclosure.
Mark Zalenski says
…with a lid of course
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.
Anne Price says
microwave is even better its a faraday cage.. even a dead one works that way..
Marc Dacey says
Why, yes, I do. It’s only on FB that my steel boat, however, is not considered in its entirety a Faraday cage, but is a horrible lightning attractor and death trap.
Shannon Kane Cullip says
Good to know… Leonard.
Beth Burlingame says
Anybody been through a lightning strike with fried electronics and had the stuff in the oven come
through ok? I understand this should work in theory, but I am skeptical of whether it will work in the real world.
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.
Gerry Morton-Haworth says
Yes! We have been struck twice and both times the stuff in the oven survived. First time just lost autopilot and lights, second time everything went, except the stuff in the oven….
Jan Bogart says
We had our inverter charger fried by a close strike to the tune of $2,000.
The Boat Galley says
Yeach. Unfortunately we can’t put the “big stuff” in the oven . . .
Jim Allen says
Would it help to disconnect your navigation electronics from the mast and nema backbone??
Meredith Wright says
Stuart Dutton…learned something new already today!
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.
Pam Dean says
I know of someone who had a lighting strike and lost all of their electronics except the iPad and phones that they put in the microwave. That’s good enough for me.
Meredith Wright says
Always better safe than sorry!
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…
Alison Stroebel says
Just don’t put them in your microwave and not tell the wife, then she puts microwave on to check if inverter is on and cooks them! true story don’t laugh
The Boat Galley says
I would never laugh . . .
Alison Stroebel says
The Boat Galley 😂😂😂😂😂😜😜🍷🍷🍻
Alison Stroebel says
The Boat Galley 😂😂😂😂🍻🍷😜
Pamela D Harwood says
If you take the rubber seal out of your pressure cooker, it will also serve as a Faraday cage.
Jack N Sue David says
Thanks for the info.
Skyler Hanson says
TY
Diane Ericsson says
The oven and microwave act as a Faraday Cage. Ask a few engineers or physicists and they can explain it.
Really. Just put all handheld electronics in the oven if there is lightning nearby. Best in a plastic container so they don’t touch metal. It works.
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.
Wanita says
Hi, Like your idea of leaving a note, perhaps what went into the oven as well.
We have never been hit but have put handhelds into the oven. Went to reach for radio and couldn’t find it for 20 min! It was pushed to the back of the oven and left when other devises retrieved!
Carolyn Shearlock says
I can so see that happening. Glad you didn’t turn the oven on, thinking everything was out!
Mike McCollough says
For sensitive electronic items that cannot be placed in cage, I would disconnect all cables, especially power and ground from the items.
Marnie & Greg Frost says
What a great tip! Thanks from a ‘weekender’ in Florida!
Lauren Montgomery says
Great article and thank you. Have you or anyone else had any luck or failure with Faraday Bags, duffels, backpacks that can be found online? Wondering if that has proven effective? Also, do these lightning mast dissipaters work or has anyone had success of failure with them?
https://www.westmarine.com/buy/forespar–lightning-master-static-dissipater–185225?gclid=CjwKCAjw8sCRBhA6EiwA6_IF4bdwV0qqCqolbMPxqrhGOaYqna4vSbI9kwkvDWTne4PUtntt4l0NKhoCjW0QAvD_BwE
Carolyn Shearlock says
Pretty much everything out there in the way of dissipators I’ve heard some people swear by and others say they had it and still had damage with a hit. The Faraday bags I’ve heard generally good things about.