Lightning Storm

PrincessoftheLake · May 12, 2011

seadaddler said:
You are anchored out for the day or night or out sailing far from port and a lightning storm surrounds you what do you do,is there any preventive things to do to prevent from losing your electrical equipment or to prevent damage or just say a prayer,
Nick

If I am out sailing away from port my inclination (assuming I have enough sea room) is to heave to. Then I remove my MFD from the helm and hide it in the oven. Then I don my foulies and say a prayer.

Marc14857 · May 12, 2011

Happened on the way to Block Island last year. Saw the storm coming from behind us and on my weather radar. Could not outrun it, so we started the engine, furled the sails, closed all ports and put on our foulies. We already had our PFDs on. Lightening striking cloud to sea all around us and gusty winds though seas stayed flat. Thats when i realized how unuseful my radar/chartplotter was in the storm as everything was red from the rain. At the time I did not know how to tune the radar for rain. I did put the boat on auto pilot and took care not to touch the wheel and any other metal such as the arch at the same time. Not sure that this did any good but I did not want to be the electrical path between the two pieces of metal. Probably should have put our handheld GPS in the oven together with cell phones. Storm lasted about 15 very long minutes. No lightening hits and no damage though it was a learning experience. Not sure that there was much else that we should have done though I would like to hear what others suggest.

Benny17441 · May 12, 2011

A slow moving sailboat is no match for fast moving thunderstorms. I'm always aware of the storms I can see in the immediate area and try to estimate their speed and direction of movement. I can heave to and let them pass by or change heading to skirt them. Unavoidably there will be some you can't escape but you can minimize the time you are exposed by heading directly into it in the opposite direction of travel. As far as lightning is concerned there is nothing you can do to divert or minimize a strike. A lightning strike will go where it will go. There is no sense in worrying about what you cannot control. The good thing is the odds seem to be heavily on our favor. Although I have heard about a few people getting hit by lightning in power boats, I have yet to hear about someone getting struck in a sailboat. I guess there might be something to be said about the "cone of protection" afforded by the mast. The majority of electrical hits responsible for instrument damages tend to occur at marinas or anchorages close to land. So perhaps being out in the open sea untheaderd to land could be a good thing. Just put your wallet and cellphone inside the cabin and grab a jacket or perhaps may be a good time to get your soap and take a shower. I'll admit I try to avoid touching anything metal during a lightning storm but I have taken showers though.

CalebD · May 12, 2011

In that kind of a situation it is best to wake up in your bed at home only to realize that you were dreaming.
I was once caught in a brief but intense lightning storm going up the East River on a MacGregor 26 S no less. It was very frightening with greenish tinted clouds and bolts of lightning hitting the nearby land around us very frequently. As soon as the rain arrived I decided it was time to finish my sandwich down in the cabin and let my friends handle the boat (4 in the cockpit was getting a bit crowded).
As I ate my sandwich below I could hear each clap of nearby thunder and feel the wind picking up with the increased heel. I've done some reading on the subject of lightning and boats and concluded that if our mast got hit by a bolt I could be blasted by a side flash of lightning from the mast which was not grounded. There was really nothing more I could do except not touch metal fixtures and eat.
It came in quickly and blew out quickly and became a nice summer afternoon again 30 minutes later.
POTL used her oven as a Farraday Cage for her electronics; a metal box that insulates it's contents from electrical charge which is not a bad idea at all. Beyond that praying is about all that is left.

Joe A · May 13, 2011

Jumper cables?

I have read where some folks dangle jumper cables from the shrouds into the water. You split the pair of cables and use one on each side of the boat. This is intended to minimize the chance of the side flash. I carry a set for this purpose but have yet to use them. I see no evidence that my Mac 26 S has any built in means of grounding the mast. So I ask you experienced sailors - Is this the right thing to do?

Bill Roosa · May 13, 2011

I'm more of the Alfred E. Newman, "what, me worry" type. If it hits then it hits if it doesn't (the more likely case BTW) then it doesn't. I do drop/reduce sail for the wind which is a much more likly source of problems though.
I also do not paly the loto as you are more likly to get hit by lightning then win.

chp · May 13, 2011

Are most sailboat mast's grounded. I have a metal plate that I am assuming was mounted on my hull to ground an old Loran unit that was in the boat. I thought this was for the mast until I removed the Loran and found the ground strap was attatched to the Loran. Would it be a good idea to attatch a heavy ground wire to the mast step. In southern Ontario summer storms in the afternoon happen almost every day in the summer.
I have a Mac 26s and I don't think any of them have this metal plate on the hull.

Bob J. · May 13, 2011

We used to get caught offshore all the time while tuna fishing. What a sick feeling being on a boat with a tuna tower & outriggers pointing high to the sky while that black wall of death comes your way. Reminds me of the movie Caddy Shack.

Tim R. · May 13, 2011

When I am sleeping I literally put my hand on the mast. We have not had any major lightning yet but our plan is to keep the salon made up that night so we can sleep away from the mast if it gets dicey.

If we are out sailing, I prepare the boat assuming that violent winds could come up instantly and wait it out. We limit ourselves to areas away from the spars and rigging.

Jerry Clark H356 SV Persi · May 13, 2011

In lightning in Steel ketch

Many years ago I made my first offshore sail with a friend of mine from Punta Gorda to Key West. He has a steel 32 foot Tahiti Ketch. We got in a tremendous thunder and lightning storm about the maximum distance we would be offshore. The night before we left, he gave me a book to read about lightning and I was glad I did. Being in a steel boat, 50 or so miles offshore with lightning striking all around is not a comfortable feeling - even after reading a book written by a professor! Since that trip, I have been in several more storms with no lighting strikes on the boat. Maybe I am just too dumb to know the difference, but I now think getting properly set up ahead of the wind gust that preceeds most storms is much more of a concern than lightning. We weren't hit and if you think about how many sailboats are sitting in marinas that don't get hit, the odds are certainly with us.

What I have been led to believe is that if the boat is grounded properly, then the boat is no different than the water and doesn't make it an attraction. True or not, it is all you have to believe in!

rgranger · May 13, 2011

Minor hijack

:hijacked:

Have any of you ever noticed that lightning strikes over salt water are orange while on land they are white? The reason is that when sodium (read salt air) gets excited (by the lightning) it emits orange as it relaxes back to the ground state. The photo below is of a sodium lamp.

Sorry if this is overly nerdy but I think it is really cool.

r

Forrest15112 · May 13, 2011

Putting electronic devices in the oven is interesting but probably not necessary. A Faraday cage is not effective if it isn't grounded but just disconnecting the device would make a big difference. The best bet is to try to improve your odds by preventing the surge from getting into your electrical system to begin with. Good grounding is absolutely the best defense, but that needs to be combined with other methods. In land based communications, we break the entire system down to potential sources of surges, either lightning directly, inductive ( nearby strike), or transient ( strike at the pole supplying ac while at the dock). Surge protectors and grounding can go a long way to keeping your equipment and you safe.

Gary_H · May 13, 2011

My Cal is grounded from the factory. this is the description from the owners manual. That being said. I'm not 100 % confident in it.

LIGHTNING GROUND
The spars and standing rigging on all Cal Yachts are grounded,
in compliance with the American Boat and Yacht Council Project
E-4, to attempt to minimize damage resulting from -lightning and
provide a measure of safety for personnel.
Each chainplate, the mast step, and all thru-hulls are attached
by means of a #8 AWG solid copper wire to the engine and/or strut.
In the event -lightning strikes the spar, the system is designed

to carry the charge by the wire to ground.

RECESS · May 13, 2011

We dropped anchor and let th storms move over us. If you sail in the south during summer it impossible to avoid them.

Is dropping anchor less desirable than heaving to?

kenn · May 13, 2011

About 11 of our little boats overnighted in a thunderstorm last year, anchored behind a spit, but otherwise open to wind (and lightning) . The storm came up in the wee hours, and it was constant rain plus near continuous lightning for nearly 11 hours... so we had quite a bit of time to contemplate. No one was struck, and from timing flashes to the boom, there wasn't a strike nearer than maybe a quarter-mile... still, a unique experience.

From subsequent reading, it seems the best practical lightning protection for our little trailer-sailor would be jumper-cables from the tabernacle to the water, to provide a high-current path to the water, and minimize arcs in/through the boat. Beyond that, just disconnecting sensitive electronics. No oven to hide them in, though.

Does anyone know if disconnecting electronic units, then shorting the unit's various inputs and outputs is sufficient to protect the unit from lightning-induced currents?

ggrizzard · May 13, 2011

POTL, What's an MFD (As FDR once mused," ...the world wonders!"). As an old school, KISS sailor, my mind is racing.

PrincessoftheLake · May 13, 2011

ggrizzard said:
POTL, What's an MFD (As FDR once mused," ...the world wonders!"). As an old school, KISS sailor, my mind is racing.

LOL-sorry! MFD means multi function display. It is the LCD screen that displays gps and radar information. Does that help?

inarathree · May 13, 2011

Like an iPhone or iPad.

Lightning Storm

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