What do you do to mitigate lighting damage?

[Hermia II]

I have for example had instruments blown out by a strike a couple of kilometers away. What one can do: Connect mast and standing rigging to earth by thick wires. Or use start cables hanging over the side. Unplug wires going up the mast as well as other antennae. Most of all, put a fully charged tablet with GPS and navigation software in the oven, it's a Faradays Box and will protect the tablet. Put your mobile phone an EPIRB and hand held VHF there as well.

[EmeraldCoastSailor]

I have put my handheld electronics in an unplugged microwave during storms. Since I carry extra chain I was thinking I'd wrap chain around mast then stays and then drop into water if I was at anchor. I carry jumper cables as well but I would not want to ruin them in salt water in case I need them to jump start from house.

[lo2jones]

Originally Posted by Lasivian

To me the definition of "Insurance" is "Poor planning".

I'm looking for ways to handle lightning beforehand. Not pay for the damage after the strike.

Many good manufacturers wire a plate into the hull connected to one of the main shrouds. Chapmans and Annapolis recommend attaching a piece of chain to a piece of metal that you place in the water and wrap the chain around a shroud or the mast. It’s been a while, I’ll be happy to be corrected on this one.

[alaskasail]

Originally Posted by Mrfish

When I lived in Florida, my 67 foot mast was the highest point in the area.

I put a jumper cable attached to the side shroud and into the water.

The theory was that the lightning would go around the boat not through the boat.

I had seen a boat with a hole blasted right through it from a lighting strike and had seen other sailors do the same thing with a cable attached to the shrouds.

I can't say it worked or not, as I never got hit after putting the jumper cable on.

Same here.
When at the dock, at anchor or just standing still, I use welding cable attached to the shrouds and splayed/fanned out at the ends and in the water below any thru-hull fittings. This gives me lots of surface area under water.

I had the tallest mast on the dock and the two boats next to me were hit, but no damage to me. I was gone so I don't know if I got hit or got any ancillary effects from the other boats, but everything was fine.

I've watched lightning strikes for many years and I still can't say that there's is *anything* I could say that is definitive. I've just been lucky.

[jpmesa]

Back in the late 80's when we went through the doldrums we always put a piece of 8' of chain wrapped around a stay and lead into the water. To give the lighting a direct path to the water instead of the boat bottom. The storms around Panama area are really scary.

[alaskasail]

That brings up the question of "To Bond, or not to Bond"

[merrydolphin]

I have lived aboard since college. Now a senior. Boats have been various degrees of grounded and ungrounded. Never been struck! Thank you God!
Most of my time has been spent in areas with LOTS of lightning like S FL. Caribbean, Central and South America etc. Have had VERY close strikes many times, where there was zero time delay. Sounded like a shotgun. Yeah. Aways scary. I don’t like it!

[Carl-T705]

Make a wide brim hat out of time foil, connect a grounding strap from the hat into.. the water, pull the hat down over your eyes and you should be fine. Cheers

[Nicholson58]

There are many old threads on this topic. Check them out.

We have been struck three times, all on the Great Lakes. He last one was a major direct hit witnessed by charter fishing crew getting set up Before dawn.

Lost:
Windex
VHS antennaes
One alternator
60 amp main shore power breaker
VHS radio
Stereo
18 glass Buss fuses
All forward cabin lights and wiring
Watchmate AIS
Simrad autopilot
Mast mount deck lights
All nav lights

What was not lost was all devices wired through a two pole mechanical switch so that both + and - wires were separated from the device by an open air gap. Simrad chart plotter, depth, radar, Raymarine stuff.

All modern electronics are always on. The button is only a wake up command. Any surge on the plus or induced spike on the negative will damage it.

[dannc]

Originally Posted by Suliwar

During thunderstorms at sea, we protect our handheld electronics by putting them into our metal cooking pots and by putting the (metal) lid on top. With closed metal cooking pots there are no holes at all in the metal enclosure surrounding the electronics inside. creating thereby a perfect Faraday-cage protection for all frequencies.

...

That is a very good idea. Much better than using a microwave.

I read a book on EMP written by a EE PhD. To stop EMP the device(s) must be completely surrounded by a metal container with no gaps. For instance, an ammo can does not provide complete protection since ammo cans have a gasket. It might work most of the time but it won't work all of the time. Wrapping the devices in aluminum foil will work as long as there are no holes in the foil.

Putting the device(s) in a metal pot, as long as there are no gaps, will work too. Our four quart pressure cooker would work great as a Faraday cage.

Later,
Dan

[GordMay]

Originally Posted by alaskasail

Same here.
When at the dock, at anchor or just standing still, I use welding cable attached to the shrouds and splayed/fanned out at the ends and in the water below any thru-hull fittings. This gives me lots of surface area under water ...

A lightning ground plate should have a total immersed area of at least one square foot. A long, & narrow strip provides more “edge” contact with the water, than does a “squarish” plate.

[fxykty]

Originally Posted by GordMay

A lightning ground plate should have a total immersed area of at least one square foot. A long, & narrow strip provides more “edge” contact with the water, than does a “squarish” plate.

I’m on a cat and have synthetic shrouds, so all this talk of ground plates and keels and the like is useless. But if a temporary solution is to wrap some 3/8” galvanised chain around our aluminium mast and lead it over the main beam into the water then that seems reasonable. Would it be enough surface area to have the chain go several metres deep?

[Jdege]

Sailing into Freedom got hit recently, on video, and has been dealing with the consequences:

https://www.youtube.com/watch?v=Df-X...INGintoFREEDOM

[Jammer]

Originally Posted by Suliwar

. With closed metal cooking pots there are no holes at all in the metal enclosure surrounding the electronics inside. creating thereby a perfect Faraday-cage protection for all frequencies.

Do your metal cooking pots conduct electricity perfectly? Do the lids have a perfect electrical connection to the rest of the pan?

[dstraton]

Apart from the issues discussed in this thread so far, I think there is a case to put a Zener diode across the positive and negative inputs into valuable electronic devices. It opens up extremely quickly and should protect the device within a certain range of lightning spike.

A friend had done this on his boat on a number of gadgets, but not all. The boat was hit by lightning. The Zener diode protected gadgets survived. The others were fried.

https://en.wikipedia.org/wiki/Transi...age_suppressor