MacGregorSailors.com

I see forespar still sells the lightning master for two hundred dollars. But...



there is the above for like twelve bucks on Amazon. For several of them.
Thoughts?

Over the years this topic has been chewed and re-chewed like a sailor's cud.

There have been discussions about trailing jumper cables, running copper wire down the mast; BOATUS even had some articles about this. The consensus is nothing works. Lightning will go where it wants, and exit where it wishes.

I wish there is a better answer. Having been caught in the middle of a lake during a torrential rain and lighting storm while sailing a dinghy sailboat, things don't get much scarier than that.

100% .... nothing will work with voltages of that magnitude.

I never had a clear understanding of what those masthead brushes were supposed to do. Somehow discharge the static negative ions or some such thing.
$200!! I had no idea they were fleeching sailors for so much money.

Russ wrote: ↑Sun Dec 06, 2020 6:16 amSomehow discharge the static negative ions or some such thing.
$200!! I had no idea they were fleeching sailors for so much money.

Me too

Russ wrote: ↑Sun Dec 06, 2020 6:16 amSomehow discharge the static negative ions or some such thing.

I'd love to read the science study that backs up any of their claims ... might be electrifying

Neo said:

I'd love to read the science study that backs up any of their claims ... might be electrifying

More like "Shocking",

I've heard that if you have a #4 copper wire, in the water, the length of a football field, attached to your mast, it will protect your boat from a lightning strike. The length of a football field in the U.S. is 100 yards.
However, the length of a football field in Canada is 110 yards, so there you would need a 110 yard long wire.

If I understand this correctly.


That spool of wire would weigh over two hundred pounds (over 91Kg). Who is handling that If the lightning doesn’t kill you, the hernia will.

Bill at BOATS 4 SAIL wrote: ↑Tue Dec 08, 2020 5:17 pm However, the length of a football field in Canada is 110 yards, so there you would need a 110 yard long wire.

And based on the fact that a lighting strike can blow a very large tree in half (extreme current!) how thick do you think that wire would need to be??
There's no stopping a direct impact when the gods are not in your favour .... And some would say that you're tempting a strike by placing a high conductivity (low resistance to earth) point at the top of your mast. And as your wire vaporizes the electrons may attempt a path (to earth) through your aluminium mast which will send splats of molten aluminium everywhere .... or you could just leave your Mac at home

LOL, Why oh WHY would anyone want to attract lightning to their boat?????? Your mast is currently insulated and isolated from a lightning strike, just park close to a yacht with a higher mast if you are worried.

NiceAft wrote: ↑Tue Dec 08, 2020 5:36 pm That spool of wire would weigh over two hundred pounds (over 91Kg). Who is handling that If the lightning doesn’t kill you, the hernia will.

100 yards of #4 wire dragging on the bottom, even more in Canada. That would make a great anchor.

In 2015-2016 I sailed the Great Loop (www.greatloop.org) solo. I was going through the Outer Banks in NC when a storm hit suddenly. A lightning bolt hit the water (missing my mast) to my starboard side about 150 yards away.

It was the diameter of a car. All the lightning protection in the world would not have stopped that if it had hit my mast.

Just saying.

charleshagen wrote: ↑Wed Dec 09, 2020 6:55 am In 2015-2016 I sailed the Great Loop (www.greatloop.org) solo. I was going through the Outer Banks in NC when a storm hit suddenly. A lightning bolt hit the water (missing my mast) to my starboard side about 150 yards away.

It was the diameter of a car. All the lightning protection in the world would not have stopped that if it had hit my mast.

Just saying.

This is why I have decided not to take any lightning protection steps. There is a theory, which may or may not be valid, that grounding the mast or adding a dissipator makes a lightning strike more probable (but maybe less damaging). I, too, have seen nearby lightning strikes, that probably SHOULD have hit the mast, but didn't. Why? Would they have hit if I had a lightning dissipator? Or if I had a mast grounding system? Who knows.

Things are complicated by the conductivity of the water around the boat, meaning fresh or salt.

So, I don't wanna make things worse by adding an unproven gadget to an X-boat that isn't really deck stepped or keel stepped, but a weird combination of the two with a stainless compression post, and lives in fresh water.

Starscream wrote: ↑Wed Dec 09, 2020 8:43 am So, I don't wanna make things worse by adding an unproven gadget to an X-boat that isn't really deck stepped or keel stepped, but a weird combination of the two with a stainless compression post, and lives in fresh water.

I'm in the same place. What little I've learned is that if you don't do it right, you could be making a bigger problem. I'd rather go with stock setup that has proven relatively safe than possibly create a bigger problem.

I wasn't serious about the 100' of #4 copper wire (110' in Canada) that would protect your boat from a lightning strike, in my post above, obviously.
I talked to the guy, that I knew from where he had worked previously, at the Strictly Sail show in Chicago, who was selling those bottle brushes that would supposedly protect a boat from a lightning strike if put on the top of a mast. I asked him if they really worked. He said that he doubted it, or words to that effect.
I've sailed where there was lightning and didn't get hit, although I sure thought that I was going to be hit.
IMO, something as strong and fast as lightning is going to go where it wants to go.
I do have lightning rods on top of my TEMPORARY WORLD HEADQUARTERS, an old barn (which was knocked down by a tornado in 1939, and rebuilt), with very large copper wire running down to the ground. Some of the glass balls on them are missing, which indicates that they were either hit by lightning, or a neighbor kid shot them with his BB gun.
The only customer, that I'm aware of, that had his boat hit by lightning, had his boat on the trailer, mast down, next to his house, had his OBM fried and had to have it replaced.
Bill at BOATS 4 SAIL