I have a small 21' sailboat kept at a dock. Now being in florida, the lightning capital, is there anything I can do to combat lightning? Ive heard of people running a cable from the mast to the keel to ground the boat, is this worth it?
LIghtning proof
- Thread starter supernailman
- Start date
- Status
Real answer? - No - nothing to combat lightening.
Do a read of the archives on this very topic, and you will soon see why.
Do a read of the archives on this very topic, and you will soon see why.
No such thing as lightning proof, but
You can take some protective measures http://shop.sailboatowners.com/detail.htm?fno=400&group=926 Dave Groshong Customer Service SailboatOwners.com
You can take some protective measures http://shop.sailboatowners.com/detail.htm?fno=400&group=926 Dave Groshong Customer Service SailboatOwners.com
Lightning is unpredictable....
I've had two close calls with lightning in 30 yrs of sailing. One was on a nice IP38 that had its mast grounded to the keel. A thunder storm came up while on the bay and lightning was everywhere. We upplugged everything, dropped the sails, began motoring into the wind, expecting the worst. Lightning actually hit the water near the bow of the boat and it was scary. The water there turned red and boiled for a short time. But it didn't hit that big mast sticking up in the air...go figure. Second experience was while moving a Passport 44 up the ICW from the Caribbean. Near Elizabeth City a thunderstorm came up suddenly and it hit the mast of the boat we were delivering. That boat's mast was also grounded to the keel. The lightning fried all the electronics and burst out the thru-hulls. We were lucky to be near shore and able to patch up the damage temporarily. We limped in under a jib. The boat was later totaled by the insurance company -- although the owner bought it back from them and eventually repaired it. Lesson learned: avoid lightning.
I've had two close calls with lightning in 30 yrs of sailing. One was on a nice IP38 that had its mast grounded to the keel. A thunder storm came up while on the bay and lightning was everywhere. We upplugged everything, dropped the sails, began motoring into the wind, expecting the worst. Lightning actually hit the water near the bow of the boat and it was scary. The water there turned red and boiled for a short time. But it didn't hit that big mast sticking up in the air...go figure. Second experience was while moving a Passport 44 up the ICW from the Caribbean. Near Elizabeth City a thunderstorm came up suddenly and it hit the mast of the boat we were delivering. That boat's mast was also grounded to the keel. The lightning fried all the electronics and burst out the thru-hulls. We were lucky to be near shore and able to patch up the damage temporarily. We limped in under a jib. The boat was later totaled by the insurance company -- although the owner bought it back from them and eventually repaired it. Lesson learned: avoid lightning.
Lightning
The bottom line is that no one knows the best way to protect oneself from lightning. Most will tell you that if you are grounded you are more likely to be hit. If not grounded, you are more likely to suffer serious damage. Chances are good you won't get hit either way. Life is dangerous.
The bottom line is that no one knows the best way to protect oneself from lightning. Most will tell you that if you are grounded you are more likely to be hit. If not grounded, you are more likely to suffer serious damage. Chances are good you won't get hit either way. Life is dangerous.
The best thing is adequate...
insurance. After that, try bonding the boat; there are many shipwright types in FL that can do that for you. BEO
insurance. After that, try bonding the boat; there are many shipwright types in FL that can do that for you. BEO
Insurance, keep the boat insured.
Anything else you may do would be like fighting a bear with a popsicle. The power and unpredictability of lightning negates any real protection you may achieve. Our dedicated scientist have not come up with a solution nor reliable data about the problem. There are two schools of thought 1) grounding attracts hits but will lessen the damage and 2) not grounding will lessen the probability of a hit but damages would be more severe. No theory has been proven best than the other. I operate under the theory of keep the boat insured and try not to be aboard when it is lightning. What amazes me is that I have heard of just one or two incidents where a person has been hit by lightning on a sailboat and I'm not sure if these even where direct hits. There is supposed to be a cone of protection from the top of the mast to a circle with a diameter equalling the length of said mast for a person inside the cone to be protected from a direct hit. Don't touch any metal parts which may induce electricity to arch through you. I have been in more than my share of electrical storms and have been blinded by lighting at the same instance or so it seemed that I was deafened by thunder, I have felt my hair stand up and have smelled the ozone in the air and I'm still here. You may call it luck, whch probably is, but I'm starting to think there is something real about that cone of protection. It;s hard to stay off the wheel in a storm and i don't think the sole of the boat shoes will provide much protection.
Anything else you may do would be like fighting a bear with a popsicle. The power and unpredictability of lightning negates any real protection you may achieve. Our dedicated scientist have not come up with a solution nor reliable data about the problem. There are two schools of thought 1) grounding attracts hits but will lessen the damage and 2) not grounding will lessen the probability of a hit but damages would be more severe. No theory has been proven best than the other. I operate under the theory of keep the boat insured and try not to be aboard when it is lightning. What amazes me is that I have heard of just one or two incidents where a person has been hit by lightning on a sailboat and I'm not sure if these even where direct hits. There is supposed to be a cone of protection from the top of the mast to a circle with a diameter equalling the length of said mast for a person inside the cone to be protected from a direct hit. Don't touch any metal parts which may induce electricity to arch through you. I have been in more than my share of electrical storms and have been blinded by lighting at the same instance or so it seemed that I was deafened by thunder, I have felt my hair stand up and have smelled the ozone in the air and I'm still here. You may call it luck, whch probably is, but I'm starting to think there is something real about that cone of protection. It;s hard to stay off the wheel in a storm and i don't think the sole of the boat shoes will provide much protection.
cone of protection only on grounded boats?
i believe i have read that the zone of protection is produced only when the boat is grounded, and is one of the main reasons for grounding. if that's true, an ungrounded sailboat would not have a cone of protection.
i believe i have read that the zone of protection is produced only when the boat is grounded, and is one of the main reasons for grounding. if that's true, an ungrounded sailboat would not have a cone of protection.
Freshwater or saltwater?
I have read several scientific surveys done that suggest a sailboat in freshwater is about 1000 times more likely to recieve a strike than one in saltwater. From my own experience and what I've read a boat in saltwater is no more of a target than the water itself, regardless of mast height. One boat at our marina, a powerboat was struck recently on top of the deck. It was right between two sailboats and the strike hit dead in the middle of the fiberglass, apparently missing all the metal parts around it; go figure. Guess the best rule of thumb would be avoid in fresh as much as possible, in salt it's just the luck of the draw. Looks like another rainy weekend in Texas after a mostly clear week, Oh well.
I have read several scientific surveys done that suggest a sailboat in freshwater is about 1000 times more likely to recieve a strike than one in saltwater. From my own experience and what I've read a boat in saltwater is no more of a target than the water itself, regardless of mast height. One boat at our marina, a powerboat was struck recently on top of the deck. It was right between two sailboats and the strike hit dead in the middle of the fiberglass, apparently missing all the metal parts around it; go figure. Guess the best rule of thumb would be avoid in fresh as much as possible, in salt it's just the luck of the draw. Looks like another rainy weekend in Texas after a mostly clear week, Oh well.
exit?
Ross: Are you certain that “the strike hit dead in the middle of the fiberglass”? Perhaps it struck elsewhere, and EXITED in the middle of the fibreglass. LordNelson is correct in understanding that “the cone of protection is produced only when the boat is grounded”.
Ross: Are you certain that “the strike hit dead in the middle of the fiberglass”? Perhaps it struck elsewhere, and EXITED in the middle of the fibreglass. LordNelson is correct in understanding that “the cone of protection is produced only when the boat is grounded”.
Cone of protection
Not sure what u r referring to when you say "cone of protection", and what would that have to do with a power boat? From my understanding, lightning, unlike normal electricity, flows on the outside of the conductors. Norman electricity flows through the conductors. The cone of protection, on the other hand is different, but yet the same in principle. When lightning hits your mast, the electricity flows down all of the rigging and if you are inside this inverted cone, your will be just fine. As for grounding? Thats another story. Lightning travels from cloud to cloud as well as from cloud to ground. It also strikes ungrounded flying aircraft, it also strikes ungrounded automobiles. Air is a great electrical insulator. Lightning can travel up to 20 miles of air insulation and then strike a boat. I seriously doubt that another few feet make much of a difference. When it comes to lightning, its all about pos. and neg. charged objects and not about grounding. Tall towers well grounded can be missed by literally a few feet and an ungrounded vehicle a few feet away will get hit. There is no predicting of lightning strikes. IMHO Tony B
Not sure what u r referring to when you say "cone of protection", and what would that have to do with a power boat? From my understanding, lightning, unlike normal electricity, flows on the outside of the conductors. Norman electricity flows through the conductors. The cone of protection, on the other hand is different, but yet the same in principle. When lightning hits your mast, the electricity flows down all of the rigging and if you are inside this inverted cone, your will be just fine. As for grounding? Thats another story. Lightning travels from cloud to cloud as well as from cloud to ground. It also strikes ungrounded flying aircraft, it also strikes ungrounded automobiles. Air is a great electrical insulator. Lightning can travel up to 20 miles of air insulation and then strike a boat. I seriously doubt that another few feet make much of a difference. When it comes to lightning, its all about pos. and neg. charged objects and not about grounding. Tall towers well grounded can be missed by literally a few feet and an ungrounded vehicle a few feet away will get hit. There is no predicting of lightning strikes. IMHO Tony B
If you are grounded
theoretically, you are no more of a target than anywhere else in the water. For this lightning traveling say, 1 mile, that puny aluminum mast is not an easier path to the ground than just hitting the water near it? If not grounded, you are more likely to be a good target..and just as likely to be a more unfavorable, depending on the charges. so what if we had an ungrounded system and attached the mast to a big coil with a charge meter at the top of the mast. One would need to monitor the charge level at the top of the mast and if it began to change rapidly the coil would have to be big enough to pump enough current into your ungrounded mast to convince the lightning to strike elsewhere! That is similar to how scientists do it..sort of. They monitor the charge and have rockets all precharged oppositely, tied to 500' of wire. when the charge reaches a specified level, they launch the model-size rocket and it unspools its wire with a very good sucess rate of GETTING HIT
theoretically, you are no more of a target than anywhere else in the water. For this lightning traveling say, 1 mile, that puny aluminum mast is not an easier path to the ground than just hitting the water near it? If not grounded, you are more likely to be a good target..and just as likely to be a more unfavorable, depending on the charges. so what if we had an ungrounded system and attached the mast to a big coil with a charge meter at the top of the mast. One would need to monitor the charge level at the top of the mast and if it began to change rapidly the coil would have to be big enough to pump enough current into your ungrounded mast to convince the lightning to strike elsewhere! That is similar to how scientists do it..sort of. They monitor the charge and have rockets all precharged oppositely, tied to 500' of wire. when the charge reaches a specified level, they launch the model-size rocket and it unspools its wire with a very good sucess rate of GETTING HIT
Might want to check Tony --
The electricians and engineers I work with always tell me electricity flows on the surface of the conductor, that is why stranded wire is a better carrier of high voltage that the same size solid wire. We were pretty sure the strike on the boat hit from the outside since there was a burn on top and fiberglass blown away underneath. Of course there are those that will tell you lightning strikes up, but I believe they are missunderstanding about a static contact charge that arcs from the ground just before the strike to complete the circuit. All of the dangerous current from the strike is moving downward. Having been caught out in the open on more than one occasion and noticing your hair is standing straight up pointed at a thunderhead in kind of unnerving. You will crawl under anything fast no matter what it looks like down there.
The electricians and engineers I work with always tell me electricity flows on the surface of the conductor, that is why stranded wire is a better carrier of high voltage that the same size solid wire. We were pretty sure the strike on the boat hit from the outside since there was a burn on top and fiberglass blown away underneath. Of course there are those that will tell you lightning strikes up, but I believe they are missunderstanding about a static contact charge that arcs from the ground just before the strike to complete the circuit. All of the dangerous current from the strike is moving downward. Having been caught out in the open on more than one occasion and noticing your hair is standing straight up pointed at a thunderhead in kind of unnerving. You will crawl under anything fast no matter what it looks like down there.
reference
No offense.. but do you have a reference for this statement below. I think it is inacurate and misleading.. "I have read several scientific surveys done that suggest a sailboat in freshwater is about 1000 times more likely to recieve a strike than one in saltwater."
No offense.. but do you have a reference for this statement below. I think it is inacurate and misleading.. "I have read several scientific surveys done that suggest a sailboat in freshwater is about 1000 times more likely to recieve a strike than one in saltwater."
Ross
Its been a long time since I had electricity class. I may be remembering wrong, but electricity is the flow of electrons. Electrons are evenly dispersed throughout the thickness ( cross section) of a wire. Has something to do with electrons repelling each other. So, if they are flowing, they are flowing pretty much equally throughout the thicknes of the wire. The resistance of wire is a function of cross section area, not of circumference. If electricity traveled on the surface, a pipe or hollow wire would present more surface area than a solid wire. The actual cross section area of a solid wire is the same as stranded wire for a given wire size. Thats why for a given wire size, the stranded appears larger tahn a solid wire. Stranded wire especiaally in the larger diameters are far far easier to work with, like in making bends and pulling long distances. Also they crush down better in wire lugs and make a better connection because of more surface contact. But dont confuse surface contact at a connection point with electrons running through the wire. Connection points have higher resistance because of this. Also, in boat use......stranded wont break from vibration. IMHO Tony B
Its been a long time since I had electricity class. I may be remembering wrong, but electricity is the flow of electrons. Electrons are evenly dispersed throughout the thickness ( cross section) of a wire. Has something to do with electrons repelling each other. So, if they are flowing, they are flowing pretty much equally throughout the thicknes of the wire. The resistance of wire is a function of cross section area, not of circumference. If electricity traveled on the surface, a pipe or hollow wire would present more surface area than a solid wire. The actual cross section area of a solid wire is the same as stranded wire for a given wire size. Thats why for a given wire size, the stranded appears larger tahn a solid wire. Stranded wire especiaally in the larger diameters are far far easier to work with, like in making bends and pulling long distances. Also they crush down better in wire lugs and make a better connection because of more surface contact. But dont confuse surface contact at a connection point with electrons running through the wire. Connection points have higher resistance because of this. Also, in boat use......stranded wont break from vibration. IMHO Tony B
Rubber mast
If the mast is an insulator, it won't conduct the lightning, will it? So - rubber mast. If you want to be really safe, replace the shrouds and stays with bungee cords.
If the mast is an insulator, it won't conduct the lightning, will it? So - rubber mast. If you want to be really safe, replace the shrouds and stays with bungee cords.
- Status