I meant that the other way around. Common sence should be used before technology/engineering.

If I remember right, that picture was after a capsize in which the mast stuck in the mud.

Nacra never had to make a settlement in a lawsuit regarding electrocution...they did, however, have to make an agreement regarding a lawsuit over a 5.2 that was taken offshore and partially sank (it was known to be leaky). Those on board decided to leave the boat for shore and met with some sort of peril. That's why post '83 Nacra boats use foam core hull construction.

I still beg to differ with your comptip assertation because the idea of the comptip is to reduce the frequency of electrocutions related to rolling a boat under a power line. It has nothing to do with lightning. I'm sure someone took an engineering, and common sense, perspective and figured that if the top three feet or so above the hound were plastic that it would prevent a certain number of injuries. The statistics that I've heard indicate that this is has preventend a lot of injury - that's common sense in my book. Personally, I would rather have my solid mast for the performance and reliability. Like I have done, I recommend that if you don't like it don't buy one.

I'm still looking for any personal experiences or incidents that people know of concerning beach cats being hit by lightning while on the water. I do recall one incident in the Worrell 1000, but I cannot remember which boat and which year and whether it was a direct hit. I do know it partially incapacitated the crew for a while.

Does anybody remember the infamous John Barnett? He told me that when he was working race committee and was on a chase boat, if there was lightning in the area, he would always snug his powerboat up alongside one of the sailboats so he would be inside the "cone of protection" -- supposedly, a stayed mast tends to deflect a lightning strike so it bounces off and hits the water several feet away from the boat.

Carl Roberts posted this on the old forum, so I am copying it over to here:



I must add to what Carl said. The theory has always been that if you attach a wire with an alligator clip to one of your stays and drag the wire in the water, when and if your mast gets hit by lightning, the electrical current is going to be led down the mast to the stay and down the stay to the wire that is dragging and will discharge harmlessly into the water.

This sounds logical in theory, but somehow it no longer seems like such a good idea when you are surrounded by lightning and you know you have made your boat into an inviting target.

First the "CONE OF PROTECTION". What this means is the lightning will hit the mast before it would hit anything within an 45 degree area around the boat. So this means if your sitting on your tramp the mast would take the shot not you. Now we're talking lightning so I wouldn't place any confidence in the cone of protection, just hope the theory holds if you take a shot.

Last year I helped a guy move his H21sc after it had taken a direct hit to the comptip. His boat was on a lift behind his house on the water. The result of the hit was the comptip exploded in half and hung by a thread. The strike had traveled down the mast and over the front beam to the port side blowing a hole in the deck box big enough to put your hand through.

Be careful out there.

Have Fun
Mike

I would not try that. Very bad science at work there. Electricity, like water, takes the path of least resistance. You would need some pretty heavy duty alligator clips (bigger than jumper cables). If there is a path, the voltage will go there.

Not good.

Mary,

I remember seeing an article in a magazine that covered lightning protection for moored mono-hull sailboats. It consisted of properly grounding the mast to the water to prevent the splintering of the electricity when it reached the base of the mast. This splintering would pierce the bottom of the hull in many, many tiny places making countless pin hole leaks. I can't remember what the article recommended but it didn't have anything to do with safety.

Certainly those sailing around the world and in the trans oceanic races have ways they deal with lightning.

I heard of one hit- Sue (Mrs. Mike) Walsh, was hit on a Hobie 14 many years ago in Jacksonville while sailing on the river at the Rudder Club. She had no apparent injuries but was all upset! after sailing in. After telling her story, some Non-believers went out and pushed over its all- aluminum mast, as a bow fitting had melted through its attachment. That is the only people on cats lightning story I have heard of- in 30 years

Dr. Ewen Thomson (Dr. Lightning) from the U. Florida Lightning lab gave a lecture to our Gainesville, Florida sailing group 4 years ago. See his excellent techical story at http://www.thomson.ece.ufl.edu/lightning/

I asked about doing a carbon fiber mast shot during the induced lightning experiments run at Camp Blanding: this involves shooting a conductive wire up into a likely cloud in summer storm conditions, to evoke a strike. It works dramatically according to their high-speed video tapes! If you have US$150,000 they would be happy to run a test on your mast. Yup- it would be hit and badly damaged...but how does that help you?

Jake, actually, they don't seem to have any good way to deal with it. Some of them ground their masts and some of them don't believe in grounding. The only cruising boats that I have seen damaged by lightning have all been ones that were grounded.

(Come to think of it, though, maybe that's because the ones that weren't grounded sank?)

Mary,

Last 4th of July I had my two young sons and my wife aboard our N6.0, headed for a gathering of friends about 4 miles away. We had rigged the boat at a ramp that faced east and we were surrounded by lots of tree so we couldn't see the weather approaching from the west. As we sailed out of the harbor and the view opened up, we could see the nasty weather building quickly in the west. We decided to head back to shore. Then, the wind died - completely. My wife was sitting beside me on the hull, holding onto a trapeze wire. Next thing I knew, she yelled, "I've been hit!" The shock caused her to nearly fall in alongside the boat.

A few breaths of air pushed us ashore, alongside a 15 foot vertical bluff with a stairway to a floating dock. Michele and the boys quickly jumped onto the dock as we sailed by it. (I had decided to run the boat solo back into the cove with the ramp. Given all the electricity in the air, it was probably a dumb move on my part, but I couldn't stand the thought of sitting and watching my boat get bashed against that cliff while waiting for the storm to pass.)

The hit that Michele took was not from a direct strike, but rather the result of the air being charged enough to conduct a shock down the wire to her arm.It was enough to make her arm go numb for the entire day.

The incident kind of freaked us out. I, too, am curious about the statistics for folks that have been hit while sailing a beach cat. Often we're sailing four or five miles from shore and coming ashore quickly is not an option. Thunderstorms can build rapidly, and to stay at home whenever they're forecast would cut into a lot of sailing time. Am I taking too big of a risk?

Reference Chapman's Seamanship (I didn't write it...) for information on lightning and the cone of protection. The idea is related what is called the Farraday Cage - surrounding yourself with conducting stuff to attract and direct the hit away from you. What apparently has been realized with boats is that doing this also seems to help bleed off potential, making the boat less attractive to hits in the first place (same thing with other tall structures properly grounded). Boats still get hit, but I'll go out on a limb and say it must be effective to some degree - there are acres of keelboats around, and rarely do I hear of one being hit. I've heard of a powerboat getting hit while underway - strike hit the ungrounded VHF antenna and blew apart the console, nobody killed but it ruined the day.

A powerboater was hit on Biscayne Bay. Unfortunately, he must not have had an antenna -- his head was the highest point, and that is what was hit. He did not survive.

This was enough to convince me that the rule of the Geneva Sailing Club (a cat club on Lake Erie in Ohio) that members must turtle their boats if caught out in a lightning storm is not necessarily a good rule.

Mary-
Last time I was out in that situation I decided the safest thing to do was pull the boat (my Taipan) over on it's side - leaving the beams ~7 feet in the air but well "grounded" in the water while I swam alongside the boat on the hull (opposite the mast side) side until the lightning passed then righted the boat. This just made sense to me at the time but I would like to hear what more knowledgeable people think of that idea (obviously it worked that time ).

Kirt

Hmmm, I had always heard that the worst place to be is in the water. Isn't that why the lifeguards make everybody get out of the swimming pool when there is lightning in the area? .....and why you don't use electrical appliances when you are in the bathtub?

Mary,
This post just shows how litle people know about lightning.
"Grounding" a boat DOES NOT prevent lightning.
On the contrary, it helps to attract it.
Lightning usually hits grounded objects like buildings, trees, antennas, LIGHTNING RODS, etc.
DUH!!!
If done correctly, grounding conducts the lightning strike to a harmless location. See: LIGHTNING RODS
As the man in the power boat found out, it isn't a matter of how high you are,
it is a matter of being the highest object in an area with a lightning strike imminent.

Lightning is certainly one of nature's most awesome forces. It is also surrounded by lots of myth and misunderstandings. With that in mind, it's good to see the interest and discussion in this thread.

Here's a source that I've used as a resource for learning about lightning safety.

National Lightning Safety Institute

Here are some stats from the National Lightning Safety Institute page. Men who hang out in Florida on summer afternoons, take note.

[color:"green"]35 YEARS OF LIGHTNING DEATHS & INJURIES

In October 1997, the National Oceanic and Atmospheric Administration published findings of some 35 years of USA lightning statistics. Fatalities, injuries, and damage were compiled for the years 1959-1994. We summarize the Report (1) as below:

1. Location of Incident:

40% Unreported.
27% Open fields & recreation areas (not golf).
14% Under trees (not golf).
8% Water-related (boating, fishing, swimming…).
5% Golf/golf under trees.
3% Heavy equipment and machinery-related.
2.4% Telephone-related.
0.7% Radio, transmitter & antenna-related.

2. Gender of victims = 84% male; 16% female.

3. Months of most incidents = June 21%, July 30%, Aug 22%.

4. Days of week of most incidents = Sun./Wed./Sat.

5. Time of day of most incidents = 2 PM to 6 PM.

6. Number of victims = One (91%), two or more (9%).

7. Deaths by State, Top Five = FL, MI, TX, NY, TN.

8. Injuries by State, Top Five = FL, MI, PA, NC, NY.[/color]

As Sam said, grounding works if it is done right. But if it is not done right, it wreaks havoc with your boat and can be deadly. And you don't know whether it is done right until you have actually suffered a direct strike. Personally, I would rather take a chance with the "Farraday Cage" theory.

Once upon a long time ago, Rick and I were delivering a Seawind 24 (catamaran) from Miami to Nassau. We had to sail straight through because we had a deadline for getting there. We were crossing the Bahama Bank during the night. It was my shift on the helm, and Rick was below sleeping. We had the boat grounded with an alligator clip on the shroud and some cable dragging in the water.

Overhead was clear, starry sky. But several miles ahead, directly in our path, was a black hole, no stars. And then the lightning began, like a picket fence across the horizon, with continual, multiple strikes from cloud to water. It was my worst nightmare.

I woke Rick and asked him if we could anchor and wait until the storm went away. Mr. Punctuality responded, "Nope, we have to stay on schedule." And he went back to sleep.

I continued sailing straight toward the electrical fence, praying the storm would dissipate before I got there.

Finally, I woke Rick again and asked, "Could we at least sail around the end of it, where there isn't any lightning?"

"Nope," said the captain. "Don't worry about it. Maintain your compass heading." Yeah, right. And he went back to sleep.

So there I was, all alone in the night, sailing toward the monster, trying to find a hole to get through where the lightning might be a little less frequent. And the whole time I was agonizing about the alligator clip, knowing that it was going to make it easier for the lightning to find me. I just wanted to make myself and the boat as invisible as possible.

So right before I got to the black hole and the picket fence, I took off the alligator clip. The stars disappeared as I sailed beneath the storm clouds. I braced myself for what I thought was certain death, while Rick slept peacefully. And then, miraculously, stars again appeared above me, and I looked back to see the black hole and picket fence now behind me.

This, of course, proves nothing. All I know is that I removed the grounding device and I did not get hit by lightning. I have always been curious about what would have happened if I had left the alligator clip on.....but not curious enough to go out and play in lightning to experiment.

The wonderful thing about lightning is it will hit anything, grounded or not. The real attraction for it is the difference in charge. Lightning can go cloud-to-cloud, or form a flash when it hits nothing particular. It can hit airplanes and rockets. One of my favorite pictures I've seen is of lightning doing a loop while going from cloud to cloud - it apparently "changed its mind", due to change in potential in the area. The only real way to not get hit is to bleed off or eliminate the difference in potential. The only other alternative is to provide it a likely path to follow if you are hit.

On big/cruising boats, ALL the big metal pieces are tied together via copper strap, and grounded to the keel or a metal plate on the hull. This makes the mast the tallest thing with the same electrical potential as the rest of the conducting bits and the surrounding water, making it the target in case of a hit - this is what gives the "cone of protection" - meaning the hit will be attracted to and follow this path instead of hitting you on deck. Again, according to Chapman's (if I remember right), there seems to be some effect of helping to bleed off some of the charge in the area, making the area less attractive. That's less attractive, not immune. If the connecting straps are not done right, the risk is higher that the strike will not follow the intended path. So, on a beach cat, unless you tie the cross beams and other metal bits together to the mast and to a sufficient grounding setup you may not be achieving what you hope to.

If you're in the water, and the water takes a hit, you'll feel it for sure - the reason to get out of the pool. One reason that they say not be in the shower during a storm.