Lightning

[john3357]

Is there a danger of being in the sailboat in a lightning storm?

[Sumner]

Is there a danger of being in the sailboat in a lightning storm?

Yes! We have been in a couple lightning storms that scared us bad. On one we took the dinghy and went ashore for an hour or so......

http://purplesagetradingpost.com/sumner ... -koot.html

................We had one on Lake Powell....





http://purplesagetradingpost.com/sumner ... r-Mia.html

......that looked like it was really going to be bad, but bypassed us some.

I've read a lot about different lightning protection methods, but haven't decided to do anything yet expect maybe have a couple cables I can attach to the shrouds with plates on the end that would go overboard.

I'll be interested in others thoughts on this. One thing I have found living in the mountain west were we get really bad lightning storms is I don't think there is any method that is fool proof,

Sum

Our Trips to..

Our Mac Pages

Mac-Venture Links

[jschrade]

With summer here, I was just wondering what would happen if my 26M were struck by lightning. I have been hit by lightning on a fishing boat, the only person that took a hard hit was the guy holding the all metal flying bridge (he got knocked down flat on the deck). The rest got slight tingles were their hands or feet were in water.

My guess is that the water provided the path to ground as it was pouring as we came in.

No question that the lightning should hit the mast, from there it will look for a path to ground. All I can think of is the steaming light connection as a path to ground on a stock 26M.

If you were dry, in the cabin and not in contact with the electronics, I cannot see how you could be in danger.

Jim

[LOUIS B HOLUB]

A nearby Marina elderly couple, former cruisers, and now retired living part time on their sailboat as local Harbormasters, told me a frightening story...

They were near the islands, BVI vicinity, when struck by lightning. Their boat was damaged badly, a large hole in the hull, all the electronics fried, and fortunately they weren't seriously hurt. They were near enough to shore for rescue.

They have a lightening "thingie" aloft now. It resembles a porcupine -- sorry I forgot the tech. name for this tool. But, observing this tool doesn't really look tough enough for a high powered lightning strike.

Lightning stories:
a green 60 ft pine tree fried, and put on fire,
a large tallow tree next to my pond, its bark peeled off, and (amazingly) no burn marks,
a neighbor's rural elect. pole shattered with elect. parts thrown 150 ft distances,
another neighbor lost 7 head of livestock in an open pasture--one lightning strike.

Amazingly, I've never seen a local "masted" boat struck by lightning -- on the water, or in nearby crowded Marinas. Amazing, in my opinion.

[THE CUSCUS]

There is a 30+ foot sailboat on the hard in my marina that was hit by lightning a few weeks ago. The strike came down the mast and out the hull in various locations, making numerous holes. They are sandblasting all the bottom coat off to check the complete hull for weak spots. What a mess!

[kmclemore]

OK. I've tried to resist as long as I possibly can, hoping that someone would start consistently spelling it correctly, but every entry here has the word "lightning" spelled incorrectly at least one or more times... and the spelling Nazi in me just can't take it anymore...

Lightening:
v.tr.

• 1.
  • a. To make light or lighter; illuminate or brighten.
    b. To make (a color) lighter.
  2. Archaic To enlighten.

v.intr.

• 1. To become lighter; brighten.
  2. To be luminous; shine.
  3. To give off flashes of lightning.

Lightning:
n.

• 1.
  • a. An abrupt, discontinuous natural electric discharge in the atmosphere.
    b. The visible flash of light accompanying such a discharge.

• 2. Informal A sudden, usually improbable stroke of fortune.

intr.v. light·ninged (-nngd), light·ning, light·nings

• To discharge a flash of lightning.

adj.

• Moving or occurring with remarkable speed or suddenness.

I fixed all the misspellings. I'm sorry if anyone is offended, but I was going nuts watching this.

[bubba]

My wife insisted we carry a couple of 6 ft long pieces of very heavy stiff copper wire with a couple of big clips on one end to clip to the shrouds one on each side of our boat. We have only been caught in a bad lightning storm last summer in the San Juan islands and we put our grounding wires on our boat. I have seen this type of grounding wires on much bigger boats at the marina because there mast was much taller than others near it. Tod at BWY's says this grounding system is as good as any, but it also can cause lightning to be attracted because of it being grounded to the water and usually if any sailboat boat is moving lightning won't strike a moving object so hopefully our anchored Mac's are moving around from a breeze and won't be hit.

[mgmathews]

I've heard of people who attach one end of jumper cables to their shrouds and throw the other end overboard.

[jschrade]

A nearby Marina elderly couple, former cruisers, and now retired living part time on their sailboat as local Harbormasters, told me a frightening story...

They were near the islands, BVI vicinity, when struck by lightning. Their boat was damaged badly, a large hole in the hull, all the electronics fried, and fortunately they weren't seriously hurt. They were near enough to shore for rescue.

They have a lightening "thingie" aloft now. It resembles a porcupine -- sorry I forgot the tech. name for this tool. But, observing this tool doesn't really look tough enough for a high powered lightning strike.

So that is where the lightning from the mast goes, Yikes! I am a tad more concerned.

Jim

[ChockFullOnuts22]

Two summers ago, a Catalina 25 in my marina was struck by lightning. The lighting fried the wiring in the mast and arched to the next dock over to the mast of a 26 or 27 ft Precision. The lightning blew out fittings in the hull and the Precision sank right at the dock.

[Russ]

What a huge topic. There seems to be so many opinions of the best way to prepare for lightning.

more reading on the topic

more reading

Dissipation array on top of mast.


--Russ

[Hamin' X]

Just a quick comment on the "porcupine thingy", for those that do not research it. It is designed to dissipate the charge that develops on your mast, not a lightning strike. It is this charge that attracts the lightning and initiates the strike. They have worked very well for me over the years on mountain top communications sites. If you decide to use a grounding system, be prepared to invest several thousand dollars. If you don't do it right, you will only attract lightning and fail to channel it to ground correctly. The result can be more damaging than doing nothing at all. I suggest further reading.

~Rich

[kmclemore]

And I suggest doing nothing at all, apart from normal smart-sailing behaviour - that is, always knowing the weather before you go out, keep track of it while you're out there, and get the heck off the water when you learn it's going to be foul. The percentage of pleasure boats that actually have a strike that injures or kills someone is so low as to be insignificant. It doesn't warrant the expense or effort to build in these kind of systems. Now, if you're an ocean-going vessel, then I can see doing something, but certainly not on a Mac.

[Catigale]

Now I understand why I loaded all those heavy things, to protect me from lightening.

Enlightening indeed - a major strike forward.

Time to bolt....

[rwmiller56]

The usual recommendation for ocean going boats, at least what I have read in many books, is to bond all the deck hardware together, including the mast, chainplates and rails, using heavy gauge strap. Below deck, all large metal, such as engine blocks, galley stoves, keel bolts, etc are bonded into grounded system, as well. The ground terminates below the waterline with a metal sheet at least 1 square foot, immersed in the water. The idea is to create a triangular "safety zone", which consists of the area enveloped underneath the mast, shrouds, forestay and backstay, including below deck. Anywhere outside of that zone, and you are in danger.

This all seems rather difficult to do with a Mac, given that it doesn't have a fixed keel and the mast is not stepped below deck. I'm not saying it can't be done, but it would be difficult and very expensive. I think kmclemore's idea is the best. Use the Mac's ability to move fast, and get yourself out of danger.

Roger