Lightning???

[Stumble]

You think that's a hole... This is a hole from a lightning strike...

[aclmck]

i have looked at many boats that have been hit some with little to no apparent damage others with massive damage but every one of these boats had 2 things in common 1. the hull/s were holed as the hit went to ground(some were as little as pinholes some above water line some below some fist sized holes)
2.All electronics were fried only simple motors escaped (no computer parts)

So if your boat has been hit get it out of the water pronto to find the extent of damage,it will have holes just that you may need a keen eye to find them, cats normally only have one hull holed but electronics fried all over the boat.

i base this on around 11 boats both cat and mono,glass,composite and wood.
Haven't seen a steely or ally that has been hit yet

[Emerald Sea]

I believe one of the other CF posts went like this....if there was a cure, your insurance company would be the first to insist you installed it.

[colemj]

Originally Posted by Richard5

Colemj, I had never seen such a thing on dry land for an individual recreational boat. Perhaps you can provide more information if only the location of the monstrosity.

It is a paint booth being built. They are pretty common in yards that do a lot of paint work - this one is in Guatemala. It will eventually be covered with curtains and air handling systems installed.

Mark

[Tday01]

There is mitigation that can be carried out.

See Marine Lightning Protection Inc.

We put an electrode at the top of our mast, and mast step is connected by heavy gauge wire to electrodes in the bridge deck and abeam of the boat and to rudder posts. All electronics are protected with surge protectors (similar to those used by the windmill cellphone tower crowd). I hope never to test it.

[GILow]

Our boat (GRP) was hit by lightening once (edit: that we KNOW about). The owner at the time used to trail chains from the main chainplates, a meter into the water, and aside from the mast antenna vapourising, there was no other damage to the boat. Needless to say, he highly recommends I do the same trick with the chains if I see a storm brewing, and the chains were supplied with the boat, so I guess I will do the same.

(This happened 20 years ago, so I reckon any subtle stuff MIGHT have shown up by now.)

[Tday01]

Ewen at Marine Lightning told us that lightning wants to go to the surface of the water, so chains just above (or under) the water would be OK.

Also why grounding to zincs does not work so well for lightning.

[DoubleWhisky]

Originally Posted by Tday01

and to rudder posts.

Sound scary to me....
But I'm not an expert by any mean...

[Tday01]

Rudder posts are thick steel rods, so can conduct very high amounts of electricity easily without melting, and they pass through the surface of the water.
Our (undersized) ground wire melted at the connection to the rudder post (probably due to corrosion in the spade connection)

[Wonderinlost]

Originally Posted by Tday01

Ewen at Marine Lightning told us that lightning wants to go to the surface of the water, so chains just above (or under) the water would be OK.

Also why grounding to zincs does not work so well for lightning.

This is only a guess about grounding to zincs. My guess is the zincs are apart of the boats main electrical system. If I am correct any electronic even if on the negative or grounded side of 12v could see the electrical surge produced by lighting. In my beliefs you would just want to give lighting a direct path to the ground and away from everything else isolated if possoble. Not so easy with a mast full of gear and electronics.

I can see the idea with the chains into the water since you are giving that energy a direct path to where it wants to go instead of finding it's way into your electrical system and grounds.

Just wondering around with no destionation to be had.

[Tday01]

The direct path (in our case electrodes and rudder post) is one side of the equation. Even if you don't take a direct hit in the 12V wires feeding anything electronic, the EM pulse is what fries everything. So the second part of the equation is to put surge protectors / voltage clamps on everything electronic.

The technology has been around for decades and applied to cell-phone towers and wind-mills. Just not worth the extra expense for boat builders.

[smaarch]

other posts confirm our experience. i posted this before and will try to find the link.
short answer: there is no answer.

[Twisticles]

I was walking down my dock a couple of months back and as I passed a Lagoon 500 there was a lightning strike on the mast. Lots of smoke and smell of ozone and brown pants.

The problem with lightning conductors (or anything metal on the mast) they have a tendency to *cause* strikes on account of providing the easiest route to earth...my surveyor buddy claims 90% of the insurance evaluations he does on struck boats are down to such "protection" and that unprotected boats seem to get hit less

Of course if you have a metal mast not much you can do about it.

My personal philosophy? Remove the outriggers and make sure I am not the tallest in the marina

[smaarch]

Originally Posted by Twisticles

I was walking down my dock a couple of months back and as I passed a Lagoon 500 there was a lightning strike on the mast. Lots of smoke and smell of ozone and brown pants.

The problem with lightning conductors (or anything metal on the mast) they have a tendency to *cause* strikes on account of providing the easiest route to earth...my surveyor buddy claims 90% of the insurance evaluations he does on struck boats are down to such "protection" and that unprotected boats seem to get hit less

Of course if you have a metal mast not much you can do about it.

My personal philosophy? Remove the outriggers and make sure I am not the tallest in the marina

+1/2. yep my experience when i was hit
we were not the biggest boy in the yard

A lot of research
most of the advice i looked at was inconclusive.
some recommended protection
others stated if you do this you are looking for a strike.
(now i agree with this)
so i carried a chain around thinking when a storm came up i'd shackle it to the backstay and drop it in.

Long story short (i suppose) Lightening is a fickle thing. either you get hit or you don't. I won't ground/bond thru hulls. I do not provide any lightning protection....been burnt already.

I sailed a long day on the very edge of a cell. beautiful sail. i definitely don't recommend it! but it was beautiful.