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Old 18-06-2011, 06:23   #76
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Re: Idiot Needs Thunderstorm Advice ( Please )

Grounding the boat does help reduce the chance of structural damage to the boat. In an ungrounded boat a lightning strike will often seek ground by exiting the boat at the chainplates or the one of the seacocks. These are damaged (there is a big hole) by the superheating as the lightning exits and the mast falls down or the boat sinks.
Grounding the boat does not eliminate the chance of these events occurring, but greatly reduces the chances of them.
(Think of like a new MB with seatbelts multiple airbags etc, you can still die in car crash, but the risk is lower than old car with no safety features).
Grounding only has a very slight benefit on reducing the risk of strike and electronic damage is also only slightly reduced, but given the reduction in the risk of structural damage its worth considering grounding any boat.
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Old 19-06-2011, 05:02   #77
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Re: Idiot Needs Thunderstorm Advice ( Please )

There was a pretty good article on this subject in the latest Caribbean Compass newspaper.....They have a website version of it also I think.

Caribbean Compass - Caribbean Yachting and Boating News Magazine
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Old 19-06-2011, 05:05   #78
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Re: Idiot Needs Thunderstorm Advice ( Please )

Jus t one little note on all the grounding and everything... I had friends that had a 50 foot fiberglass sailboat. They were hit near Thailand.... He said that the boat sank within 4 minutes..... the boat was professionally grounded. Apparently every single wire on the boat caught fire, the keel bolts sheared and the grounding wire exploded......they spent three days floating in the life raft before a trawler picked them up. Said he couldn't believe it. Sometimes I guess it doesn't matter how much preparation went into it... lightning just has tooo much POWER to disperse through grounding wires.
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Old 19-06-2011, 06:21   #79
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Re: Idiot Needs Thunderstorm Advice ( Please )

Quote:
Originally Posted by Mark Johnson
“More people are killed "per year" by lightning ...”
Quote:
Originally Posted by Therapy View Post
I have never heard that. It is hard to believe. It would be in the thousands would it not?
Yes.
An estimated 24,000 people are killed by lightning strikes around the world each year, and about 240,000 are injured*.

* "ANNUAL RATES OF LIGHTNING FATALITIES BY COUNTRY" by Ronald L. Holl
http://www.vaisala.com/Vaisala%20Doc...by_country.pdf
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Old 19-06-2011, 07:19   #80
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Re: Idiot Needs Thunderstorm Advice ( Please )

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Originally Posted by zeehag View Post
i havent pix ofth ebendytoy that keeps getting hit in slidelllouisianna- butt he second time, the lightning damage went half way tothemans house and he HAD lightning protection--tells me it doesnt work..LOL--firstt ime was 6 months to repair his boat, second time i amnot sure if is 1 or 1 1/2 yrs, or a total write off. LOL that is a NASA ENGINEER WITH STATE OF ART PROTECTION FROM A RANDOM INCIDENT..lol
Well... I have no "pirate", "Donald Duck", or any other alter egos, so skipping the foolishness, and in plane English:

#1 Lightning doesn't care what the profession is of the owner a structure.

#2 "Lightning Protection", = Grounding structures, does not keep them from being hit or being damaged, any more than good tread on your tires totally prevents wrecks! What "lightning protection" does, is give the strike a more direct, lower resistance path to ground, so it will not HAVE to go through the structure. It VASTLY improves your odds of survival, while minimizing damage to the structure. This has been statistically proven, beyond a shadow of a doubt, for decades.

#3 NO amount of anecdotal evidence, giving cases where the structure was damaged in spite of being grounded, changes anything. If it has a lightning rod, LARGE copper conductor, and straight path to large copper ground, the odds of survival for both the structure and it's occupants are VASTLY improved. (Perhaps X 100)

Life is full of ways to be taken out before your time. We can't "prevent" our exit, but we can most certainly "postpone" it. I choose to drive with a well maintained vehicle with good tires, and install a proper lightning protection system on my boats. It is totally rational for others to just "not want to go to the trouble", but it's not rational to claim "they don't improve one's odds" as the reason.

Like so often happens, the OP's original question is getting lost... I apologize for my contribution to this. On your charter, the length of time you'll be out there is so short, that lightning is the least of your worries! (Your odds of being hit during one week, are like thousands to one against).

HOWEVER... Know what you're doing, anchor well and set the hook hard, (I even dive on mine), keep a sharp watch, don't hit anything, and don't fall off of the boat. Then, while onshore, dress down, don't wear jewelry, be polite, and don't be out late at night drunk. THESE are ways to improve your odds as well, and way more risk to ignore than the fact that most charter boats do not have lightning protection.

Be smart, be careful, and relax! ENJOY YOUR VACATION, you'll be fine.
Mark

BTW... The information that I have shared with CF regarding the subject of "lightning Protection" is not "my opinion", or the result of reading an article or two. It's the result of years of research (HUNDREDS of articles), while I was building my boats, my being an ABYC member and considering their recommendations, as well as paying for the results, (video & book), put out after a multiyear study done by the U of Fl on a government grant. I looked for a consensus! With all things "science", you look for a consensus of opinion. There is a strong one here. Science isn't perfect, it's just the closest to real "answers" that we will ever come.
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Old 19-06-2011, 07:42   #81
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Re: Idiot Needs Thunderstorm Advice ( Please )

if grunding makes boats not have so much damage, then splain to me whyit is the bendytoy 50+ of that nasa engineer in slidell louisianna that has been hit 2 times in 4 yrs WITH HIS NASA ENGINEERING STATE OF THE ART grounding gizmos has major damage. and damage to half way to his house. rofl.
no thankyou. i will remain UNgrounded and keep my boat
the scientifical studies i have read ALL proclaim lightning as random and not predictable and nothing protects ye from it.
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Old 19-06-2011, 07:57   #82
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Re: Idiot Needs Thunderstorm Advice ( Please )

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Originally Posted by zeehag View Post
bendytoy

Now be nice, darling, and use the proper name.

Otherwise you will slip down my Valentine Card list and I will buy you a cheapie from the supermarket instead of hand engraving my thoughts of you on a slice of teak.


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Old 19-06-2011, 09:24   #83
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Re: Idiot needs thunderstorm advice (please)

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Eww, that would be tough on the hands!
Actually it's the magnetic field the lightning sets up which in turn creates another electric current in all the nearby metal, which then courses through you. Someday someone will figure out a way to recharge batteries with lightning...
I've actually seen the LED on my boats solar controller light up in the middle of the night with an approaching thunderstorm showing that the solar panels were charging the batteries. I bet it wasn't much current but, every little bit is welcome IMO.
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Old 19-06-2011, 12:13   #84
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Re: Idiot Needs Thunderstorm Advice ( Please )

My understanding is that once it strikes, often a number of bolts occur from the main bolt. You dont want to be in their path to ground or water. I doubt if the screws in your bunk will attract, but a larger piece of metal might... like Wheel/pedestal/rudder post might be attractive...(right down the mast on the backstay and jump to the wheel....through your head!) The rudder post might be the most attracive ground to water on the boat..albeit a little out of the straight line course..
Just a point of interest: In the Carribean my Passport 47 had the vhf antenna and windex melted and I never knew it occurred until I saw the windex gone and went up to see the damage. Black traces were obvious to the stbd upper shroud anchor.
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Old 19-06-2011, 12:24   #85
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Re: Idiot Needs Thunderstorm Advice ( Please )

rofl--i havent that much metal on my topsides--i am sooo happy with my formosa... wood masts, wood wheel, feline and crocks in place--i am SAFE!!!!!

oh yes,and absolutely NO lightning protection....... rofl other than my feline and crocks......alllis gooood.... have a great time!
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Old 19-06-2011, 12:53   #86
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Re: Idiot Needs Thunderstorm Advice ( Please )

I have a keel stepped mast and there is a heavy wire from the mast shoe to the keel. I got hit, right on the masthead. When we hauled the boat for inspection there was "treeing" (burnt paint looking like tree roots) at all the through hulls although the through hulls are not bonded. The lightning went all through the boat from stem to stern. There was even treeing on the rudder at the gudgeons. The charge is so great it just goes everywhere.
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Old 22-06-2011, 07:33   #87
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Re: Idiot Needs Thunderstorm Advice ( Please )

One big variable is the amount of "charge" each strike contains. The anecdotal stories of "well grounded" boats being destroyed are most likely due to these "super bolts" that can overun even the best grounding systems. The vast majority of lightening strikes are the smaller bolts from the bottom of the clouds, a much rarer strike is the superbolts from the top. If hit by a "super bolt" you would need copper wires over a foot thick to dissipate charge. Fortunately the vast majority of strikes are much smaller and recommended wire sizes can dissipate charge. Any metal object can pick up induced charges from a nearby strike and should be grounded.

If you work on a sky scraper and a steel I-beam is dropped on your head no hardhat will save you, but the vast majority of dropped objects are things like screws and small handtools. That is why they are required...the common incidents, not the exceptions.
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Old 22-06-2011, 08:00   #88
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pirate Re: Idiot Needs Thunderstorm Advice ( Please )

Do'nt stand under any trees.... wooden masts are very attractive....
Don't hang onto the standing rigging....
Reef down and then either sail on or heave to and go down below... chances of being hit are no bigger than your house being hit...
Ain't life fun....
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Old 22-06-2011, 08:04   #89
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Re: Idiot Needs Thunderstorm Advice ( Please )

i like that,boatman--lol i hide under feline with crocs on and rubber suit handy--donot wear a tinfoil hat..it will make fried rains.... rubber hat... remember--UNDER feline....when his fur rises, take feline and run somewhere--you will both get hit...dont hold on to mast....
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Old 22-06-2011, 08:22   #90
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Re: Idiot Needs Thunderstorm Advice ( Please )

We were having a drink with a couple whose wife is totally paronoid about everything so we don't try to mention 'the war'. But my mate was blabbering about going through electrical squalls with his radar ON so he can get outta the sqaull quicker. I said thats CRAZY because the radar, half way up the mast with electricity going through it would atteact anything....

Of course the couple listening were both thinking me and me mate are nuts, or all sailors are nuts, and they're gunna die.

I told them they were gunna die. (I didn't mention it might be when they're 85)


So Radar ON or Radar OFF?



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