Lightening Strikes

[delphys44]

Have had 3 lightning strikes on my 46’ sailboat over last 6 years in my slip. Serious electronic damage each time, as would be expected.
Same marina. South Florida.
Any thoughts on moving my boat closer to an 8 floor hotel building. Change slip location?
Or just except as an act of God or bad Karma and nothing I can do short of moving boat north for summer/spring or buying a boat without a mast?
Thx.

[leecea]

Google found this in the online Britannica.

On structures less than 30 metres (about 100 feet) in height, a lightning rod provides a cone of protection whose ground radius approximately equals its height above the ground. On taller structures, the area of protection extends only about 30 metres from the base of the structure.

Sounds like you'd have to be close to the hotel to get protection.

I have read of people adding lightning protection to their boats. Not sure if they work.

[dannc]

Get lightning protection for the boat.

I have seen lightning hit some structures but not others that were all the same height.

I have seen shorter trees hit by lightning while taller nearby trees got hit.

I have seen trees, not only less tall than other trees, but lower in elevation, get hit.

I have seen men fixing roofs, with hammers held high in the sky, while lightning advanced down an island hitting power poles on each block but then skipping over those roofers.

Best I can figure, to minimized the chance of a boat getting hit by lightning, or minimize damage, the best thing is to install lightning protection. Then cross fingers, pray, roll the dice, etc.

[CarlF]

If there was a lightening protection system that actually worked, the insurance companies would make us install it. Lightening claims are the 2nd biggest cost to insurance companies after hurricane damage because of all the electronics in modern boats. Claim size s often over $100,000.

Moving close to a building taller than your mast would help. Also, a lot of damage in a marina comes up the shore power cable from other boats. Pay some marina kid to unplug your shore power cable when thunderstorms are coming.

[dannc]

Originally Posted by CarlF

If there was a lightening protection system that actually worked, the insurance companies would make us install it. Lightening claims are the 2nd biggest cost to insurance companies after hurricane damage because of all the electronics in modern boats. Claim size s often over $100,000.

Moving close to a building taller than your mast would help. Also, a lot of damage in a marina comes up the shore power cable from other boats. Pay some marina kid to unplug your shore power cable when thunderstorms are coming.

Land structures are protected against lightning and it works.

I think the ABYC and NFPA were/are working on updating lightning protection standards. Here is an ancient document from 1992, https://nasdonline.org/7182/d000007/...rotection.html that discusses what I have seen in more recent documents.

Trying to be in the zone of protection of a taller building or mast may help. May. I have seen many lightning strikes where the tallest object was NOT getting hit. I have also seen a lightning bolt strike out of a the blue sky. No clouds in sight. The front was 20-30 miles away.

Disconnecting from shore power is a good idea if one knows a storm is on the way. Just disconnect much sooner than one thinks needs to be done.

[tsenator]

Originally Posted by dannc

Trying to be in the zone of protection of a taller building or mast may help. May. I have seen many lightning strikes where the tallest object was NOT getting hit. I have also seen a lightning bolt strike out of a the blue sky. No clouds in sight. The front was 20-30 miles away.

Disconnecting from shore power is a good idea if one knows a storm is on the way. Just disconnect much sooner than one thinks needs to be done.

Being in the "Cone of protection" helps protect people from a strike , but it doesn't help electronics . I've had electronics blow out from a lightning strike on the water that was 100 yards away. The "EMP" was enough to blow out sensitive IC's (Integrated circuits) .

[dannc]

Originally Posted by tsenator

Being in the "Cone of protection" helps protect people from a strike , but it doesn't help electronics . I've had electronics blow out from a lightning strike on the water that was 100 yards away. The "EMP" was enough to blow out sensitive IC's (Integrated circuits) .

The cone might prevent the boat from getting hit but, as you said, it is no guarantee that damage will be prevented. It might but it might not. It Is lightning.

We had a tree a hundred feet from our house hit by lightning while I was looking outside to see if the front was nearby. I was one the phone looking at the sky when everything went WHITE, we lost power and the phone connection. Somehow, no damage was done, other than my underwear. I really expected damage to electrical equipment, but thankfully, nothing was damage. Somehow. The tree that was hit is 30-50 feet from our power line which I expected to have sent a big power hit into the house but we got lucky.

[Kettlewell]

I think it mostly comes down to pure dumb luck, despite any protection system you have. In fact I have spoken to several people with metal boats who were struck with huge damages resulting. Most of us with fiberglass and wooden boats will never be as well grounded as one of those metal boats. Here's the Practical Sailor take on lightning: https://www.practical-sailor.com/blo...ut-dissipators

[Thomas1985]

I think I read multi hull sailboats are significantly more likely than monohulls to get hit. No idea why, but I think insurers claim cats are almost 7/1000 and monohulls are 4/1000.

Maybe move closer to a catamaran and see if he takes the next strike?

[Montanan]

Don't confuse "Lightening Protection" as in avoidance, with Lightening Conduction" systems.

One desires to conduct the massive electrical energy safely through or around the structure. Lightening will hit that which the charge path avails, but once it hits something one can direct the current through the path of least resistance.

Sensitive electronics get whacked by the electromagnetic field effect not just from direct conduction.

Florida storms and lightening strikes are just a part of the landscape.