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Was out yesterday on Long Island Sound in on and off showers when the strangest thing happened. I could see a rather menacing looking shower coming our way but not thunder and lightening so we stayed drifting 9we were fishing). As the storm approached but still 4-5 miles away, we began to hear crackling coming from the top of the mast. touching the mast, engine, etc produced no effect. Turning off all circuits and electronics produced no change. Turning everything on and starting engine produced no change.

As I began to think maybe some sort of charge was being built up on the boat, we headed for the harbor. As we departed, we heard distant thunder. By the time we got back to harbor no further crackling. We went back on the water in sunny conditions for another 5 hours with no crackling.

Any ideas of what I experienced? My only thought was that we were building up a positive charge due to the potential negatively charged atmosphere. I have heard a positive charge must develop oposite a lightning bolt. Is this true?

My guess is St. Elmo's Fire. And you're a lucky boy.

There are several kinds of lightning. Either can strike 5 miles away from any noticeable rain or hail storm. Last year the military and goverment agencies were encouraged to modify their safety plans based on the latest research.
For more go to: http://www.lightningsafety.noaa.gov/science.htm

Sounds like a situation that happens all the time to me. Since Ive owned my boat (going on our second year) the cracking sounds and sparks, have happened almost a dozen times. It shuts off my electronics, makes my navigation light flash, and keeps you from touching anything metal.
Prev thread: Shocking

The worst was when it blew a fuse in the motor, leaving it useless and us stranded on the lake. This was a good thing in disguise. It forced us to return in windy, rainy, and stormy conditions under-sail.

Ive adopted a technique from Richard OBrien. I just clip a piece of wire on one of the shrouds and toss the other end into the water. While one would think that you could attach it to the lifeline and it do the same, unfortunately Ive had no luck with grounding the lifelines, just the shrouds. Im still deciding if I want a more permanent and visually appealing fix than having the boat look like its dragging a set of jumper cables, but on the other hand, the audio and visual reminder that lightning is approaching is nice. Just for the record, the poor mans grounding system that I use, is not to keep me on the lake, its strictly to get me home. Typical sparking conditions dont allow me or anyone to come in contact with anything metal, so, dropping the sails and keeping the motor running become a problem.

---Harrison

Would that grounding system attract lightning?\

Here at Zuma Beach, we never even hear thunder. I think I've heard about 10 thunderclaps in 10 years, and they are always associated with strong. cold winter lows coming in the back door.

Years back, I had a 26D on Lake Superior... We sailed all day, with a Bayfield 32 (friends)... Late in the day, we stopped at Stockton Island (Julian Bay)..`Happy hour, food and bed (too much sun also)... Later in the evening while anchored next to the Bayfield 32, a passing thunderstorm hits us... We had a grounding plate tied to the Backstay (if lightning hits directly, it blows out the sail locker)...

Suddenly lightning is everywhere. Flash and bang! Very loud! After the storm, we look out... Our friends have lost everything on their boat: no lights, radio, anything electronic is toast... Nothing happened to us... The next day. we had to help them start their boat (battery gone) and followed them back to Bayfield, WI.....

I talked with a fellow EE that deals with lightning and RF... He said that because the Bayfield had a higher mast and bad luck, I was spared and he was hit....
JR

Yes, I have heard that a grounding system on a boat increases the chance of a lightning strike, however, doing nothing to my boat creates static charges so severe, you dont want to be on board. That is why I havent installed a permanent, grounding method. I like the early warning system (cracking, sparking etc.) rather than waiting until I see lightning or hear thunder to alert me to get off the water. Sometimes skies look better than they are. With a permanent system, that first strike may be me!

---Harrison

So I was right to be concerned. We were definitely out in front of the storm although I saw no arcing and all my electronics were fine and the motor ran fine. Pretty scary stuff.

The arching I usually see is where the shrouds and lifelines cross. Theres approximately 1-2 inches of and air gap, and the quickest arcs are 2-3 times per second! Like I mentioned, once when this was happening, I clipped my jumper cables on the lifeline, and tossed the other end into the water over the stern. Nothing happened. I then clipped it to the shroud and bingo! The cracking and shocking stopped. This leads me to believe that the upper rigging is the culprit.

---Harrison

>Was out yesterday on Long Island Sound...<

Hey Chris... you were lucky. By coincidence... I saw this post by
a friend of mine on another sailing newsgroup that I monitor. He and
his friends have their boats berthed over at LIS.

Best regards

Bill
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"An ex-girl friend's Pearson 10M was hit by lightning a few days ago. She went
aboard for the 1st sail of the season and found nothing worked....electronics
dead and even the bilge pump was dead.

Insurance was called and now she has the long process of a proper survey and
replacement of just about everything, which will take some time. Hopefully the
hull is not compromised. What a drag.

It's strange that every lightning strike I hear of at City Island is on a mooring and
never at a slip. Everyone I spoke to says this is just luck since our marina is just
1/2 mile away from her mooring area."

We've had this discussion before, several times. One is so old it fell off the end of the board.
This one, Lightning protection options, runs to seven pages and 101 posts.

Opinions of experts vary so widely that it's quite difficult to make any reasonable conclusions on what would be suitable for use on the Mac, or any other small trailer boat, for that matter.

Without bringing the whole sorry mess up again for a rerun, I believe one thing upon which most of the experts agree is that the jumper cable in the water technique is at best a waste of effort.

Just a slight rehash from before. Grounding your boat's rigging will only make it more attractive to lightning. Your best protection is to dissipate your charge buildup into the atmosphere via a static wick.

Marine version, or Electronics version.

I have been using the electronics version for years on mountain top tower installations, with no strikes. Other towers around me, have trouble all the time. The same idea has been used on aircraft for years.

Rich

Chip wrote: I believe one thing upon which most of the experts agree is that the jumper cable in the water technique is at best a waste of effort.

The Jumper cables are not intended to protect me or the boat from a strike, nor do I sail around with them deployed. They get used AFTER I'm sparking, and ONLY as a quick remedy until I get off the water. Like I've stated twice already in this thread, they only come out to allow me to keep my motor running, and/or drop and secure the sails for a safe trip off the water. Their remedy is instantaneous. That in itself is not a waste of effort.

The Static Guard that HaminX refers to looks interesting and most likely will be a mod I do soon, but in the meantime, (since I cant go a day without being on the water) Ill toss my cables in the water should I unexpectedly get charged.

---Harrison

Here is a site -

http://www.thomson.ece.ufl.edu/lightning/

Hamin' X wrote:Just a slight rehash from before. Grounding your boat's rigging will only make it more attractive to lightning. Rich

I honestly don't know much about lightning, but It seems to me that the dissipators make a lot of sense as you've indicated. I can't understand how the grounding would make it more attractive once it was grounded? Wouldn't the difference in charge be negligible at that point? I noticed with my boat before I added the cables that the charge would build up over a few seconds, and then I'd get shoked , and dischare with my aluminum boat hook. Since the cable is always in the water, the charge never builds up? Comments?