Lightning Hits Sailboat: How Often Does that Happen ?

[noelex 77]

The chance of a lightning strike is reasonably low, but there is an old medical saying. It is not rare if it happens to you.
I got hit a year ago, no stuctural damage, but most electrics needed replacing.
It is a pity that the chances of being hit a second time are no different than the risk of the first hit. I have had my go it is someones elses turn.

[trinescape]

do you think it matters if your mast is aluminium or timber ?

[sailstoo]

Originally Posted by trinescape

do you think it matters if your mast is aluminium or timber ?

Good question. What if it's carbon fiber? Is one material a better conductor than the other? Absolutely. But is one material a better attractant than the other? I dunno. How about it from one of you EE types?

[bewitched]

OK - who can answer me this one?

Something I see quite often is a cable clipped to the rigging and the other end into the water. The theory is that this will give a quick and easy route to ground for the lightning.

But... does this mean that you have made your boat more prone to a hit because you have provided it with a easy way to ground?

[Stillraining]

I have often wondered why drilling rigs aren't hit more often then they are...I have worked them for 8 plus years and never took a hit.

when your spudded in over 10 to 20,000 feet I would call that about as well grounded as you can get ...yet it doesn't attract lightning anymore than a player on baseball field or golf course.

I don't believe grounding has diddly squat to do with rather you are more attractive to lightning or not, just what happens to you after the fact.

[SariTimur]

As Mark J said we were hit in Phuket in January. Actually not a direct hit, it hit the water right next to us but it still wiped out all of our electronics. We have aluminium masts and a grounding plate which is also connected to the rigging. The story goes further as we were next to a boat in Singapore in November and it got hit wiping out some of our electronics. All the boats around us had some minor electronics wiped out except the boat who took the direct hit was really bad off. So two lightning strikes in 23 years owning the boat but they were with in two months of each other. Go Figure! Oh incidently the boat in Singapore that took the direct hit it was his second hit with in a year as well so as Noelex says just beacause you got it once doesn't give you immunity

[senormechanico]

We "almost" got hit twice in one day.

About 20 years ago, we motored from our house on the Sammammish Slough diagonally across Lake Washington (Seattle) on a summer day in a 13' Boston Whaler to visit relatives. We had a high speed prop on the boat, but we also had four adults and a bunch of stuff aboard, so we couldn't plane. It was 5 knots maximum, so we putted.
We were about halfway through a 3 mile crossing when we noticed all the puffy clouds were going from right to left all around us and the sky overhead was GREEN!
Next we noticed everybody's hair was standing up!
I got the bright idea that if I put my hand in the water that my hair would not stand up, but was told it stood up even higher when I did that.
Oops.
We started praying , HARD.
Got to our destination less than a minute after the rains opened up.
We were soaked to the skin almost instantly.
Visited with the relatives, dried clothes, wore robes, etc.
The sky cleared and it was sunny.
A few hours later it was time to go home again, so we left.
Halfway across the lake, the same conditions quickly set up again!!
Hair up, praying, the whole 9 yards.
No hit either time.

A week or so later (we were Commodores of PSCC, the local cruising club) we got Jeff Renner, a local Meteorologist weatherman to do a presentation for our group.
When I related our experience, his eyes got very big and he said, "You were at ground zero and within seconds of being hit !!"

[Puddlefish]

Never hit by lightning on a boat, but got hit on a commercial jet once. It hit the wing about three feet from me as I was looking out the window. I thought it was as cool as heck, the other hundred screaming passengers seemed to think otherwise. The pilot called it a "weather event" when he was attempting to to calm everyone.

[GordMay]

Originally Posted by senormechanico

...
Hair up, praying, the whole 9 yards.
No hit either time.

A week or so later (we were Commodores of PSCC, the local cruising club) we got Jeff Renner, a local Meteorologist weatherman to do a presentation for our group.
When I related our experience, his eyes got very big and he said, "You were at ground zero and within seconds of being hit !!"

Indeed!

[starfish62]

I got hit last summer in West Palm Beach, Florida. Fried the VHF & AM/FM and blew up my new Orca Marine Group LED Anchor/Tricolor (ouch!) and the whirlygigs. Other than that, no damage. There was a Colombia bubble top for sale here that had been hit three times! Talk about bad kharma.

[svHyLyte]

I have often wondered why drilling rigs aren't hit more often then they are...I have worked them for 8 plus years and never took a hit.

One of the members in our Club is with FP&L and I asked him a similar question about their power towers. It seems the FP&L puts lightening dissapators on each tower (see Lightning Master Product Showcase ) and I know they are used on platforms. While many people dispute their validity in our experience the only boats we know to have been hit have not had one, whereas we, and adjoining yachts have been (relatively) safe. Do they work? I can't say, but after 18 years of sailing in Florida, we've not been hit (knock on wood however).

FWIW...

[CptnBrent]

I ran a bar in Key Largo and this topic came up. Of the five sailors at the bar, every one had been hit at least once and one had his boat sink under him. Fourteen years, two boats, no problems for me. Then I moved to Clear Lake, seemingly the Lightning Capital of the Free World. My boat was hit twice, both at the dock. Both strikes were witnessed.

First time was major damage, just about totalled the boat, caused a fire, lost everything electrical/electronic. Lightning hit 50+ boats on Clear Lake that day and the house next to me. It took me six months and a lot of carpentry/electrical work to bring 'er back. I checked my grounding system, found the mast and standing rig was NOT grounded properly, corrected same. I made it a point to wire everythign straight runs, no loops that could become inductive coils and start fires (check that stereo wire, folks!), minimum crossing of wire. All should be good, right?

Boom! Second time was minor, although the witness saw the lightning strike the top of the mast and blow sparks everywhere. The little Catalina lightning cone definitely had a melted look when I scaled the mast. I lost some electronics, easily replaced. Went back to the drawing board, did some more research, regrounded the mast with bigger cable, gentler bend, added the standing rig into the loop, added a lightning diffuser at the top, clip-on galvanic fish to the backstay, and checked the dock wiring.

The dock wiring was pure *****, and were I to guess, I'd say it played a role. I had been assured it was all per code, in good shape, etc. It actually had a connection at a low point that was filled with water and a tee that branched off to an outlet UNDER the dock I had also been assured was dead. It wasn't. I made a straight run, #6, from a new dockhead back to the power box.

I now make it a policy not to leave her plugged in unless I'm on-site. This may be over-cautious, but I'm not a liveaboard, so I'm good with it. Next time I have her hauled, I'm going to add a grounding plate, separating my lightning/boat ground from my electrical ground.

Kudos to my Allstate agent. My first strike was thru another insurer and was a six-month nightmare that at least ended well. 'Nough said. I changed insurers. My second strike, which caused minor damage, was taken care of swiftly and professionally by the Allstate adjustor.

[speakeasy]

Hmmm. I was lead aircraft in a flight of 2 A-6's in Vietnam in '68 flying at 20,000' in the goo when my refueling probe was hit with lightning. My wingman said it came off my wing and hit his aircraft. My instument panel blinked, but everything continued working. Why? At the time, I just thought it must have been a small charge, not a full on bolt. The probe sticks up in front of the windscreen.

[mintyspilot]

Aircraft have a metal skin so the charge travels over the outside of the aircraft. The only non-metal aircraft I know of that had problems with lightning was a GRP glider at London Gliding Club. The lightning penetrated the wing and travelled up the metal control rods until it reached the bell housing which was composed of a different metal. The resistive load caused the joint to heat the air explosively inside the wing and it blew the wing apart from the inside.

The instructor and pupil (who was on his first ever flight) parachuted out. The full accident report is at http://www.aaib.gov.uk/cms_resources...pdf_500699.pdf

[nautical62]

This according to Boat U.S. Seaworthy.:

"What are the Chances of
Lightning Striking Your Boat?
The following statistics are based on all of the BoatUS Marine Insurance claims for lightning damage over a five-year period. The percentages suggest the chances of the various types of boats being struck in any given year.

Auxiliary Sail .6% Six out of 1000
Multi-hull sail .5% Five out of 1000
Trawlers .3% Three out of 1000
Sail Only .2% Two out of 1000
Cruisers .1% One out of 1000
Runabouts .02% Two out of 10,000"


I believe this is on all insured vessels, not just cruising vessels and may not be representative of passage making.

BoatUS.com - Seaworthy Magazine