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Old 08-08-2012, 17:25   #1
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Lightning Strike Damage Details Needed

I have read through 857 (This was not an exhaustive search) postings on lightning strikes on cruisers forum and found no instance of lightning causing harm to humans on sailboats. One person did get a shock while holding onto a tiller, but no injury was reported. This was for sailboats; lightning strikes on powerboats kill 10 to 13 people per year in the United States depending on data source. Most of these fatalities are for open top fishing boats. Another possibility for sailboat fatalities would be that a through hull could get blown out while underway and cause the sailboat to sink with loss of life, but none of the postings mentioned that happening. As for lightning hazards in sailboats, much of the concern is that lightning could do a side flash, say from the mast to a through hull and sap anyone in the way. However, I have seen the idea on cruisersforum that lightning goes to the stays and shrouds and hence to the through hulls and other grounds by way of moisture in the fiberglass. Also, especially in freshwater, pinholes at the water line can be caused by a lighting strike perhaps from the same mechanism down the shrouds and stays. Lightning strikes prefer to dissipate on the water’s surface. If side flashes, possibly through humans, and through hull failures from side flashes are the norm, then I think we need to estimate the likelihood of death from this.

If anyone has experienced a side flash on a sailboat, either visual observation while down below in a lightning storm, or by inspection of tanks and other metal items that have pin holes or anything else indicating a lightning side strike, it would be I think valuable information to share for human safety in sailboats. If there was a side strike, was the mast properly grounded to a square foot copper plate under the boat or to an external metal keel? Other valuable information would be the observation of through hull damage if the mast were properly grounded or not.

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Old 08-08-2012, 17:45   #2
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Re: Lightning Strike Damage Details Needed

Happen to be researching this topic currently though I have no firsthand info.

Side-flashes occur even on boats where the mast is grounded because SOME of the energy comes down the shrouds and stays, then needs to go to ground, usually by jumping to adjacent metal objects, if bonded the energy goes to ground, if not bonded it arcs to the grounding system or it arcs to the waterline if that is closer, going thru hull and causing damage usually.
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Old 08-08-2012, 20:49   #3
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Re: Lightning Strike Damage Details Needed

I have seen an insurance report (with photos) of a strike that went down an ungrounded forestay. It side flashed to the chain in the chain locker and then continued through the FG hull to the water. It burned a large (inches) hole in hull above the waterline.

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Old 09-08-2012, 08:05   #4
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Re: Lightning Strike Damage Details Needed

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Originally Posted by Viking Sailor View Post
I have seen an insurance report (with photos) of a strike that went down an ungrounded forestay. It side flashed to the chain in the chain locker and then continued through the FG hull to the water. It burned a large (inches) hole in hull above the waterline.

I have seen that photo also. What might have happened is the strike came down the forestay and possibly also the shrouds, through the fiberglass and then out at the chain locker. If a side strike happened, there should be a visible entry point into the fiberglass at the inside of the hull with possible pin point spots on metal items in between. Fiberglass does absorb water and therefore would be conductive, especially because of the minerals left in the fiberglass, the cause of blisters. Boat surveyors have moisture meters to check for entrapped water because of blisters, and balsa that has become water logged. If the strike went through the fiberglass, then it would be unlikely that a cross strike would take out a human. My belief it there is an awful lot of speculation about what happens with a lightning strike, but little actual verification and all we have to do is some inspection after the fact. We could have comparison between protected and unprotected sailboats, the unprotected could of course serve as a control group.
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Old 09-08-2012, 08:43   #5
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Re: Lightning Strike Damage Details Needed

neighbor of mine was in the la cruz anchorage when hit by a bolt last month--ony thing hit was his wifi antenna--left a black mark on his electrical panel. the storm was directly overhead, as they form here directly over us. boat not lightning "protected."
another boat in the marina, this time, received a hit that was seen in punta de mita, 10 miles away as a huge green glow-- he was "protected" and blew all his electronix out. thi swas 2 weeks ago.
might want to research the stats on how many sailboats get hit by lightning and which ones were allegedly protected and the damage incurred with and without protection scams in place. from my personal eyeball experience, more damage is incurred WITH alleged protection than without. i do not believe in attracting something to your boat that would rather be elsewhere. the alleged protection dreamed up by the vendors for keeping damage minimal doesnt work and does attract the bolts to your allegedly protected floating lightning rod.

everyone has different experiences with lightning--ask the NASA engineer in slidell about lightning protection-- both times he was hit--and damaged to the point of sinking and other incidental damages about engineering lightning protection for your boat..... yes he was hit, in same place, 2 times in 4 yrs. first time was 6 months in repairs and second time was a write off.
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Old 09-08-2012, 08:56   #6
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Re: Lightning Strike Damage Details Needed

I think the insurance folks and professionals who do real research arrive at the opinion of:

"You can't reduce your chances of being hit, but boats that have some form of preparation on average fair better than those that don't".

Could mean running battery cable down the mast or clipping some jumper cables onto a stay and tossing one end in the water.
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Old 09-08-2012, 09:02   #7
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Re: Lightning Strike Damage Details Needed

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Originally Posted by zeehag View Post
the alleged protection dreamed up by the vendors for keeping damage minimal doesnt work and does attract the bolts to your allegedly protected floating lightning rod.
This is bad advice that is given without any statistics or references. A couple of "I know a boat that..." do not substitute for research or data.

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Old 09-08-2012, 09:07   #8
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Re: Lightning Strike Damage Details Needed

when it is my neighbor and is real, is better than stats which can be skewed any way the statistician wishes. yes i took statistics also. why dont you go sailing in some lightning to find out the REALITIES instead of the what ifs.....i HAVE been sailing in it and i know many souls who have been also--have you??? do you?? if you did, you would not be seeking answers to unaswerable questions in a forum.
everyone will have a different experience in lightning--no two are similar---- if you want REALITY-- dont ask the questions.
i gave you REALITY from REAL TIME experiences- take it or leave it-- protect your boat so mine is safer. rofl.

i know the name of the wifi dickieantenna hit--he is my neighbor--boat name octavia. i donot know the name of the spectacularly hit catamaran on dock 10 that blew the darkness away from the night. i also dont kno w NAME of the 55 bendytoy that was detroyed in slidell, but i sailed out of the dock across from him for a near year.
if you dont like my answers--GO SAILING to learn reality.i havelost any respect i may have had for those who cannot understand the actualities of being there and knowing the souls who were hit. bad advice???? SAIL IN IT-- then you will see how bad the advice is. thankyou. stats are skewed for whatever purpose needed. i prefer reality to stats.

ps--data is collated from reality and skewed into your version of info---isnt reality.
are you out living in th elightning n a lightning rod??? be there, do this before stating ho w inaccurate the info is when you are hit and not considered as proper input. you forget i am IN lightningville, mexico--much more intense than floriduh....btdt, both places. and there are worse lightning centers than even fla and mexico-- go sailing there to learn if you cannot take reality input as such.
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Old 09-08-2012, 09:57   #9
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Re: Lightning Strike Damage Details Needed

Don't know if you are addressing me, since you respond to someone seeking answers on this forum and your posts rarely make sense to me, but we are living and sailing aboard full time in lightning prone areas. We have also taken a direct lightning strike, so have a bit of experience with the stuff.

We have never suffered any hurricane damage, despite spending many years in an active hurricane zone because our refusal to make any storm preparations on our boat has kept the hurricanes away from our particular area and caused them to instead hit all of those boats in FL and NC who drew hurricanes to them by preparing for them.

I can point to thousands of boats who have suffered severe hurricane damage while we have gone unscathed, so I know what I'm talking about here.

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Old 09-08-2012, 10:13   #10
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Quote:
Originally Posted by colemj
Don't know if you are addressing me, since you respond to someone seeking answers on this forum and your posts rarely make sense to me, but we are living and sailing aboard full time in lightning prone areas. We have also taken a direct lightning strike, so have a bit of experience with the stuff.

We have never suffered any hurricane damage, despite spending many years in an active hurricane zone because our refusal to make any storm preparations on our boat has kept the hurricanes away from our particular area and caused them to instead hit all of those boats in FL and NC who drew hurricanes to them by preparing for them.

I can point to thousands of boats who have suffered severe hurricane damage while we have gone unscathed, so I know what I'm talking about here.

Mark
I had to reread that a couple of times. Funny.
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Old 09-08-2012, 10:24   #11
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Re: Lightning Strike Damage Details Needed

My boat was struck at pier 39 in Sanfran.,amidst a sea of masts it chose mine.Boat is bonded.We were sleeping,strike shook the boat.The vhf antenna is highest point at masthead.When leaving S.F. couple days later tried to use radio,didn't work.Discoverd the wires for power and coax on back of VHF radio were melted slightly.I repaired wires, radio still worked for a few months then packed it in.Replaced radio,had no other problems.I now have one of those dissipators at masthead.
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Old 09-08-2012, 10:28   #12
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Re: Lightning Strike Damage Details Needed

each and every single strike is different-- you may choose to disbelieve folks other than yourself-.
i dont care who ye are-- everyone in lightning zones suffers different experiences. if the experiences of others does not match yours or the insurance company and their stats, then dont discredit the ones who also live and sail in the stuff. someone not desiring to hear the info doesnt have to read it. it is from ACTUAL experience, not statistics, which are skewed by insurance companies to promote their scams.
in this particular area, down drafts and updrafts ar ethe norm. lightning is intense and will be in the clouds forming around you. this is a storm formation zone. incredible to watch storms forming over head.
the 2 main schools of thought with lightning are
protect with attraction equipment.
donot attract and make sure that which you own is not hit.
choice is to the boat owner individually unless dictated by a clause in you r insurance policy.
as for protection--i take the example of those being destroyed by hits --they are the "protected" (BY LIGHTNING ATTRACTORS) boats--as opposed to the gentler hits of the "unprotected ' boats who have suffered slight problems as a result of the hits endured.
the nasa engineer who lost his boat to lightning TWICE despite his efforts t protect his bendytoy 55 from it.
enjoy your alleged protection. i will enjoy my boat.
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Old 09-08-2012, 11:41   #13
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Re: Lightning Strike Damage Details Needed

Zeehag It's not correct to refer to lightening ground devices as attractors. There is lots of information on other threads, but everyone with any scientific knowledge continually points out that grounding a boat (slightly) decreases it chance of a strike. The important message, which we risk loosing, is that grounding signiffancly reduces the damage from a strike.

There is no financial incentive in suggesting grounding the boat. Grounding is achieved with copper cable readily available from numerous vendors. Even for these vendors, cable sales for lightning grounds, will form a tiny fraction of their sales.

I don't discount your real world experience, but many others have similar experience. I have been hit by lightning and seen other boats that have also been hit. Other posters have similar experience yet disagree with your conclusions.

You obviously have a belief that grounding a boat attracts lightning. Everyone is entitled to their view on this forum, but its a risky view, because the experts tell us an ungrounded boat can suffer significantly more, perhaps life threating damage, without this grounding. It will be slightly more prone to getting hit as well.

When it comes to safety issues you need to be prepared to carefully justify your advice when it goes against convential wisdom. Experts have been wrong before, but more than a few isolated cases will be needed to alter such widely accepted practices.

Stay safe and hug the cat if all else fails
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Old 09-08-2012, 12:04   #14
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Re: Lightning Strike Damage Details Needed

Man am I glad I was not out on the boat Tuesday evening, we had over 1600 lightning strikes in 5 continuous hours of storm cells each carrying wind gusts and torrents of rain!

I have never seen Vancouver get anything like it, apparantly the jet stream was aimed right at us and carried these cells over us one after another. One bolt hit within a block of our house while I was sitting on the porch ...kaboom!
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Old 09-08-2012, 12:11   #15
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Re: Lightning Strike Damage Details Needed

There is no company selling lightning "protection" and no one debating lightning "protection". There is no practical way to "protect" a boat from lightning and zeehag does a grave disservice to the discussion by constantly conflating minimizing the damage from a strike with preventing a strike from happening.

Providing a robust path for lightning to get to ground does not attract lightning. In fact, all controlled studies and actuarial evidence so far points to just the opposite.

No insurance company is running a scam to make you install "lightning protection systems" so that you are more likely to get hit by lightning and suffer losses they will pay for. That logic is seriously flawed.

Presenting conflicting opinions to properly researched topics is not "information" unless supported by valid data and/or references.

I personally know 11 boats struck by lightning this year. Seven of them had no bonding or other forethought to lightning and four did. I don't draw any conclusions from this because I don't believe it is a large enough dataset, but feel free to draw your own. In fact, even adding your own personal examples to the list, it would not support your thesis.

A lack of experience with a lightning strike is not expertise with lightning. An experience with a lightning strike is not expertise with lightning. I have never given birth, but do not consider myself an expert in child bearing. I have built a bookshelf, but do not consider myself a carpenter.

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