MacGregorSailors.com

I'm not sure if the boat getting hit while you're in it is necessarily an automatic death sentence. As was mentioned before, the lightning will simply look for the path of least resistance to the water... in the case of our boats, wouldn't that be down the compression post and into the water through the centerboard cavity? Another possibility would be through to the aft end of the boom then to the motor, which, of course, would be VERY bad news for you if you happened to be at the helm.

Anyway, on our last trip we had one stormy night to deal with, though we were at a marina that night (with taller masts surrounding us... call that yet another 26X advantage!). Still, we made it a point to stay away from the compression post, all of us hanging out up in the v-berth to watch a movie (though the DVD player was hanging from the compression post... it undoubtedly would have gotten fried in the event of a hit).

Regardless, I guess when you're dealing with such massive amounts of electricity, there's no way to predict where it will go or what it will do if/when it strikes your boat, but some basic precautions (such as staying away from the compression post and the helm area) would, I think, dramatically improve your chances of surviving.

Oh, and I may have mentioned it before, but my lightning protection system consists of some heavy welding wire wrapped several times against the base of the mast (with insulation still on), and about 10 ft. (with insulation stripped) trailing in the water off both sides of the boat. The theory is that for those who believe that grounding the mast invites a strike, this does not actually ground the mast (since the cable wrapped around the base of the mast still has insulation), but in the event of a strike, the close proximity of the copper wire to the mast makes it easy for the lightning to jump across and hopefully be channeled to the water.

Then again, as Moe recently pointed out, my mast is grounded anyway because of my VHF antenna at the top and the motor bracket being in the water. So, I either need to install the ground isolation device he mentioned, or disconnect the antenna cable at the radio when I know a storm is coming.

--Mike

1st dclark . . more than likely your right . Its looking for ground and it most likely will hit the taller of the mast . If your talking inches or a couple feet its a real coin toss if its 5 or more feet your looking better every inch your shorter . . see length does matter
Over all IMHO and I do a bit of this for a living as stated before .
Do as you may you cannot do enough. Yes if you had a elaborate system weighing in at maybe several hundred pounds of useless junk 99.9999% of the time you might help but you might also attract .
Insulated wielding cable wrapped around mast ??? Its raining your boat is at least a little dirty and the strike may well follow the contour of the surface rather than try to penetrate the insulation . As stated by several there is NO WAY to predict the path force the path etc etc.
IF ??? you talk to someone selling these system he may well sell you on the need . If he doesn't he should be fired from his job as that is his job SELLING you on the need.. We sell systems they are a VERY MINOR part of the overall cost of a small 30 million dollar building btw well under a 100,000 sq feet one story . They are sold on how little it cost to take things to another level of protection.
IMHO if you have the money and everything else you can think of has already been bought go ahead If it makes ya sleep better that's fine. Its what we call a false sense of security BTW

For those that may be investigating /assembling their own lightning arrestor/Dissipator system... The following Plaited drain wire is available for a good price as part of a lightweight deployable protection system. Add a dissipation grid, mast clamp, and plait conectors for a complete system

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Lightning does follow a well defined priority list to determine where it will strike.

1. Any uninsured boat.
2. Any boat on which the insurancy policy has just expired.
3. In order of priority based on the amount of the deductible with the largest deductible first down to the lowest priority being the guy carrying extra lightning strike protection with no deductible.

A lot smarter minds than ours have tried to figure it out. They were all successful at it. They all contradict each other too. The most believable ones are the ones willing to sell you their protection device they have developed.

Tony,

hmmm
I seem to be missing your point....
I am not selling my designs, nor recommending for any particular individual or situation....Those that need it know it. Those that can define the problem and model the geometery and the electrical phenomena and component parameters can devise solutions.

however.......differences in systems do not guarantee to make them less effective. The geometry of each vessel allows optimization of many protective measures., and to the untrained eye....may look like many different solutions.

Lighting has many properties.....and protecting most aspects and approaches to a vessel is difficult. but not impossible. We protect, aircraft, transmission lines, structures.....etc...

I have to take you to point on your statement tho...


your comment...

A lot smarter minds than ours have tried to figure it out.

is technically in error.

they arent a lot smarter......and we have figured it out. The department of energy, utilities, scientists and engineers have many working models and codes....we have built labs that generate lightning.....on the scale of real world discharges.... Your information, Whatever the source is not current. WE do the math every day!! we know how much energy is in strikes of various kinds......(both from area modeling, and actual strike measurement), we know how much energy it takes to melt 40 lbs of conductors in 28 microseconds...

I didnt spend 17 years in our institutions of higher learning and 21 years at our labs and not learn a few things.

I remember when I was young and dumb and naive..(vs. just being dumb now)..I believed that all the important technical decisions made by our government and laboratories were made by intense scrutiny, objective evaluation,,,,,and by a panels of experts who knew an order of magnitude more information than the average technical whiz .....

not the case.....

Im still looking for that proverbial genius who is an order of magnitude smarter..... hull, I would be happy to meet him if he was even just 10 times faster....let alone 10 times as much information and knowledge.


PPPL, HFPL, Los Alamos, LL, Hanford, INEL, Batelle, Aberdeen and Redstone.... I have worked with hundreds/thousands of very smart people. Electrostatics.....High energy discharge..... plasma physics.. There is a lot or research in these fields.

Dont assume that because you do not yet know how to calculate or design a solution to a problem that others do not.

be careful trying to convince the electrical engineers and physicists here that they do not know what they are doing. I have helped design and build a proton accelerator in a friends shop....Others are far crazier than I....
Tho having a radiologically controlled area at home is kinda cool......

and my largest tesla coil to date had 1-1/2" copper water pipe for the primaries.... heheheheh........ when we talk about corona discharge around here ...............it aint peeing away the beer.....

Now maybe I misread your comment......
and I enjoyed the mirth in the hierarchy (priority list)of lightning targets....with some resistance and reluctance.....(sorry about the bad EE pun),

And probably most of the readers of this forum will never try to solve the simultaneaous equations to determine a partial solution to capture, arresting and dissipating system..... But............

I know of several that are investigating it.

If your problem with my listing was the fact that I only listed one component...... It is because I am not designing anything for someone else.......

And maybe.... I should just relax and get back to work....But I am a difficult sell, I have read and built much....and most of the "systems" for vessels I have seen do not have an engineering basis......or at least not one that the individuals could discuss the properties and the component parameters....

There are more kinds of vessels out there than aircraft...... and vessels have many more ......modifications than the external surfaces of aircraft. Thus designing for any given boat will require many unique parameters, preventative maintenance and inspection of components.....

This does not make the problem impossible. Sorry about the length of the discourse....Hope I have not reoffended any members here....

JMHO

Waternwaves,

Sorry there, you took my comments way too seriously. I did not intend to offend anyone here nor was I referring to any comments made here by anyone. I was meerly referring to the neumerous articles I have found on the internet that cover lightning strike protection and end with an ad for some miricle discovery such as a piece of copper you attach to the top of your mast to disperse the ions etc. At the end of the day (gads I don't believe I just used that expression.) no one can explain why at a marina a well protected boat is just as likely to be struck by lightning as one without any protection. A point that has also been pointed out in a couple of articles. It is almost impossible for a layman to dissiminate the missinformation from good information. They all make sense and none of them make sense. The only real facts we have is that some boats have been struck and most will never be struck. No matter what anyone does the odds of being one of the ones to never be struck are far greater than the odds of being struck. Please don't take any of my comments so personaly. I don't attack people.

Hmm.. I just took it that you were injecting a bit of humour and having a bit of fun, Tony... not that you were taking a shot at anyone. And as to your latter statement, I agree and I think that's pretty universally true - vendors will always try to twist the 'facts' around to make it seem as though their product is the only 'solution'... particularly in situations were the facts are often misunderstood or in dispute, as with lightning protection. And when a vendor starts using statistics to prove their point, that's when it's time to turn and run!

Food for thought

There are roughly 50 lightning strike fatalaties (all kinds) in the US each year.

Over the period 1959-1993, in Florida (a Boat Heavy State) 14% of lightning strikes reported on people were associated with on-water activites. This is the highest rate of water lightning strikes I could find on google.

So there are probably fewer than 7 deaths per year as a result of boating and lightning strikes...

In contrast 700 of us drown each year while boating - many highly preventable by use of PFDs and moderation of alcohol.

Ok, ok, damn it, Ok! I'll wear my PFD... Just back away from my alcohol!

I can see it now, the skipper trips on the lightening suppression/guidance system tumbles over the ankle height stanchions and into the drink!!

That's the point of all this. . . makes little sense to install seatbelts on a motorcycle.

I used to have a sanctioned five point harness installed in my Triumph for when I crashed (never did, knock, knock) yet I would throw my leg effortlessly over the saddle of my Yamadog 1100cc crotch rocket and fly down the road at fatal velocities.

What is the exposure? What's the risk?

Michael

Cat's numbers minimize the danger of lightning. If you live in Florida or Colorado, be sensible about it.
Yeah, 14% of deaths reported were boating related. Read further though. 34 to 56% of strike locations were thrown in the "unknown" category, and you know these statistics are a wag anyway, they weren't tracked as accurately in 59 as they were in 2003, and even then plenty of EMTs have better things to do than fill out forms. Great statistics when over one third end up in the "unknown" pile. Also about 3 or 4 people are injured for every one killed.

Lightning is the #2 weather killer. It kills more people than tornados, hurricanes, and snowstorms, only floods kill more people. Also, Florida is 1st for fatal stirkes but Colorado is ranked 10th?! Not because Colorado gets that much lightning, but because more people are where the lightning tends to be. Worthy of concern if you find yourself on coastal Florida or Texas. If you have lightning storms 5 days a year zip up your jacket and stay out of the beer. If you're in LA watch where ya wear red and when y'all come down here to sail I highly recommend you make yourself short when the afternoon storms roll in.

My '02 26X (Silver Girl) was hit by lightning last year while on a lift behind my house. It destroyed the VHF antenna atop the mast (found the stainless part on the dock later) and destroyed the radio of course. It also fried the auto-pilot, both batteries and all of the electronics on the outboard. I have no idea of the path, since no part of the boat/motor was in the water.
Al

I wasn't trying to minimise lightning danger Argonaut...I was deliberately using the statistics on the conservative side and pointing out that drowning far exceeds the risk of lightning strike from the (albeit simplified) view point of the number of deaths.

Using Florida's 14% reported will likely overestimate the number of boating related lighting strikes. In most other states, I bet the percentage of boat-lightning deaths is much less. Even with this bias (using the 'high percentage'), we still estimate 100 people drown for every one killed by lightning.

I dont know how you guys do it down in Florida - when I see lightning up here I run for shelter. I think if you did that down there you would never boat.

I'm not a native of Florida nor am I an expert on their weather. I have however, taken several vacations over 30 days long there. I always found the storms to be quite predictible. You can count on them to arrive at almost exactly the same time every day. Just make sure you are off the water at that time and you will miss almost all of the storms.