Lightning

[floater81]

if your in the open ocean and you fing yourself in a thunderstorm what are the chances of your boat being struck by lightning and if struck what kind of damage will there be? is there any universally accepted way to prevent damage from a lightning strike?

[sabray]

Gord may had an excellent link to the best grounding method prior thread. Otherwise it's good fortune random you die or live. Mostly we live

[onestepcsy37]

we got hit two months ago in the sea of abaco.

while sailing we were overtaken by a tight little thunderstorm. the admiral was down below and i was in the cockpit. there was suddenly the loudest BANG i ever heard and i saw a blue light come down the mast. it was over so quickly there was no time to be scared.

the damage was somewhat, although not entirely, random. the lightning apparently hit the radio antenna, the highest object on the boat, and literally vaporized it. it simply disappeared. a few of the light bulbs were blown out, but randomly on different circuits. the vhf radio, the depthsounder, and the navtex receiver were all made inoperable. i have no other hard wired electronics. my hand held vhf's and gps's were all ok. interestingly, the devices that were hard wired to the battery rather than through the breaker panel, survived. they are the autopilot, the refrigerator, and the inverter.

the boat is NOT grounded. i've thought about grounding but could never convince myself that it was a good idea. i doubt if i would have had less damage if i was grounded.

[zeehag]

sailed in it for a near year in gulf of mexico. didnt get hit. live in it here in mazatlan. praying i dont get hit....wearing crocs to repel it as crocs do not attract anything.

only boat i know was hit was across from the place in slidell we sailed from.... he is a nasa engineer with full on engineered protection that seems to have failed totally now, twice.
as a result, mine is not protected except by my cat, but i do have jumper cables as i was advised i shoul dhave em for being in a bad storm. now all i gotta do is remember to go out in the mayhem, and place em....yeah right.

[FSMike]

Originally Posted by floater81

if your in the open ocean and you fing yourself in a thunderstorm what are the chances of your boat being struck by lightning

Slim.

and if struck what kind of damage will there be?

Impossible to predict.

is there any universally accepted way to prevent damage from a lightning strike?

Sink the boat.

[zeehag]

i have been at sea when in a lightning storm. nothing happened except kat and me hid on the bed and prayed hard off watch. i jumped a lot on watch--involuntarily....

[osirissail]

There is a "new" system out for lightning "protection" on boats. Saw it in Yachting Magazine and the link to the system is: Siedarc electrodes
- - This is not a lightning prevention system but a system designed to supposedly protect the boat when a lightning strike occurs. In fact, it appears to invite lightning strikes much like lightning rods on barns, etc.
- - The main difference between classical lightning strike protection and this system is the addition of arc electrodes just above the waterline inserted into the hull much like through-hulls.
- - It uses a standard below water grounding plate and the "Siedarc electrodes" just above the waterline to dissipate the energy from the lightning strike without, supposedly, harming anything in the boat.
- - Very interesting concept but the installation of the system seems to be rather involved and expensive which may be why they are advertising in mega-yacht magazines.

[zeehag]

i will let them try it for a bunch of years and continue with my passive protection plan.

[Adamante]

Originally Posted by onestepcsy37

interestingly, the devices that were hard wired to the battery rather than through the breaker panel, survived. they are the autopilot, the refrigerator, and the inverter.

Wait... so you're saying your autopilot, refrigerator, and the inverter wiring is not protected by breakers?

[tropicalescape]

I was told that a boat on Lake Norman was hit by lighting or did it touch a power line?... any way it was told that it blew small holes into the hull..said it looked as thou it was shot with a rifle..and then it sank..What someone said anyway..

[pillum]

My deck stepped mast is bonded to the cast iron keel with a 70sqmm cable. In lightning storms (when they are unavoidable) I connect a couple of battery charger leads to the backstay and drop the ends over the stern.

Other than that pray to Lir or whichever other Gods you worship.

[S/V Alchemy]

I got a steel boat. It's in essence a Faraday cage. Doesn't mean I want to get hit, and it doesn't mean I wouldn't consider unplugging a number of critical systems in a lightning-heavy storm.

That said, seeing lightning hit water in the Atlantic about 200NM north of the Virgins was one of the most beautiful things I've ever seen

[pillum]

Originally Posted by S/V Alchemy

That said, seeing lightning hit water in the Atlantic about 200NM north of the Virgins was one of the most beautiful things I've ever seen

I was in the Gulf of Mexico in early August, with lots of storms all around us. One of the night watch-keepers saw a strike to the sea a couple of miles away, he said it was spectacular, a strike, then a bloom of blue climbing back up the strike. Frightens the life out of me, but I wish I'd been on deck and had seen it, he said it was one of the most scary but beautiful things he's ever seen at sea.

[callmecrazy]

It's known that freshwater boats suffer more damage than saltwater boats. Due to the 'side flashes' (or something), that damage the hull at the waterline. (google it)

With that known, you can deduce that proper grounding is important. A lot of people beleive that If the boat is not 'grounded' it is less likely to attract lightning in the first place (because lightning is 'looking for' the quickest path to ground), which may, or may not, be true. But the facts that are known show that IF lightning strikes, it will follow a clear path to ground, as opposed to spreading it's wings looking for one.. When it has a clear path, the damage will be limited to objects directly in that path and random electronic damage from the Electrostatic discharge.

[onestepcsy37]

adamante -

the devices that are hard wired to the battery - autopilot, fridge, and inverter - are protected by inline fuses of the size recommended by the manufacturer. those devices were not damaged and their fuses were not blown.

the electronics and the blown light bulbs all went through the breaker panels. the breakers were not tripped but the devices were damaged as i stated. other bulbs and devices wired through the breaker panel were not damaged.

i failed to mention that the engine alternator was also blown even though the engine was not running at the time.