New lightning stats from BoatUS Insurance

[markpierce]

Would a lightning rod be helpful in reducing damage if not the risk of a strike?:

[Brob2]

Originally Posted by colemj

For example, multi's are twice as likely to get struck overall than monos, but the percentage of all multis <40' is very low, while the percentage of all mono's <40' is very high. Yet overall, boats >40' are 3x more likely to be struck than boats <40'.

Difficult to see the above relationships being coincidental.

Mark

God has made his choice.

[colemj]

Originally Posted by markpierce

Would a lightning rod be helpful in reducing damage if not the risk of a strike?:

Well first, look at DotDun's map. I don't think you need to worry about lightning - rod or no rod.

Second, the purpose of a rod is to direct the strike to something that can carry it to ground. It is not designed to reduce the probability of a strike. So if yours is connected to an appropriate conductor that is terminated in an appropriate ground, then it may help to reduce damage.

Third, for a lightning rod to be useful at all, it must be the highest point. You have antenna higher than it.

Mark

[markpierce]

Originally Posted by colemj

Well first, look at DotDun's map. I don't think you need to worry about lightning - rod or no rod.

Second, the purpose of a rod is to direct the strike to something that can carry it to ground. It is not designed to reduce the probability of a strike. So if yours is connected to an appropriate conductor that is terminated in an appropriate ground, then it may help to reduce damage.

...

The mast rests on a fiberglass roof, but the seven guy wires lead to a steel hull.

The lightning rod is sharper/more pointed than the antennae.

[colemj]

Originally Posted by markpierce

The lightning rod is sharper/more pointed than the antennae.

But it is not higher.

Mark

[markpierce]

Oh well. A VHF radio is cheap compared to an overall lightning strike.

[Ziggy]

Originally Posted by colemj

That would make sense only if the number of multis in lower latitudes were twice the number of monos. I don't think this is the case.

The statistics given in terms of strikes per 1000 boats, not the absolute number of strikes. So if most multis are in Florida, while the monos are more evenly distributed up and down the eastern seaboard, the multis will have a higher odds of getting hit. That may not be the whole story, but I think it is a part of the explanation.

Originally Posted by colemj

BTW, while FL may be the lightning capital of the USA, I can assure you that it is not that of the world! We have been in places that Floridians there cannot believe…

Good point. I don't know where the highest incidence of lightning is on the globe. Florida is the highest in the U.S.

[LeaseOnLife]

Originally Posted by Ziggy

...I don't know where the highest incidence of lightning is on the globe.

this looks like a winner:
Catatumbo lightning - Wikipedia, the free encyclopedia

http://www.weather.com/news/news/eve...tning-20140201

Not many cruisers there, if any. I'd like to see it, but not from a boat.

Dirk

[DotDun]

Originally Posted by markpierce

Oh well. A VHF radio is cheap compared to an overall lightning strike.

Problem is it won't stay in the VHF/antenna/coax/radio....it'll jump out to something else, then something else, then something else, then something else, and maybe find ground.

[groundtackle]

What do this stats mean? Strikes per 1000 what? Boats? Lightening Storms? Years?
We need context to Jane meaning



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[groundtackle]

Originally Posted by nshawdvm

What do this stats mean? Strikes per 1000 what? Boats? Lightening Storms? Years?
We need context to Jane meaning



Sent from my iPhone using Cruisers Sailing Forum

God I hate spell checkers


Sent from my iPhone using Cruisers Sailing Forum

[DotDun]

Originally Posted by nshawdvm

What do this stats mean? Strikes per 1000 what? Boats? Lightening Storms? Years?
We need context to Jane meaning



Sent from my iPhone using Cruisers Sailing Forum

Hmm, let's try this.....from the BoatUS article....

about one in a thousand boats has a lightning claim each year.

So maybe they mean that for every 1000 multihulls, 6.9 get struck by lightning each year.....????

Is that the context you're looking for??

[colemj]

Originally Posted by markpierce

Oh well. A VHF radio is cheap compared to an overall lightning strike.

Here is how that works (this is from direct experience of having our VHF antenna take a strike): The lightning hits the antenna, travels down the coax to the radio, jumps onto the negative side of your DC system and proceeds to take out anything and everything connected to your DC system until it finds its way out through your DC bond to water (typically through the engine). You will lose not only the electronics, but your alternator, windlass, possibly starter, fridge, inverter - where it may jump over to your AC side and start wreaking havoc there, etc.

It can become very expensive in milliseconds after hitting the VHF.

But put this in perspective - how many close lightning storms are you experiencing in SF Bay area? For comparison, in Panama these occur every night and often in the day for 6 months of the year.

Mark

[colemj]

Originally Posted by Ziggy

The statistics given in terms of strikes per 1000 boats, not the absolute number of strikes. So if most multis are in Florida, while the monos are more evenly distributed up and down the eastern seaboard, the multis will have a higher odds of getting hit. That may not be the whole story, but I think it is a part of the explanation.

Well then in addition to parsing the data by LOA, it would be good to see the data presented by area. I would be interested if monos in FL are struck at the same rate as multis, for instance.

I know from direct personal experience of ~30 boats hit by lightning in Panama that there is no difference in hit rate between mono and multi. Even when adjusting for the numbers of each type. However, that is definitely not a large enough sample to draw any conclusion.

Mark

[jaybird1111]

I'd like to see the data filtered from the perspective of how expensive multihulls are than monohulls are (alluded to earlier).

Ergo I'd suggest that: given that multihulls in general are more expensive than monohulls, that the multihull owner is more likely to file a claim than the less-vested monohull owner. Similar to the length argument, the data may be skewed thusly