[C320-list] Lightning

[Jack Brennan]

The consensus I’ve read from lightning experts is that the dissipators probably don’t do any good, although there’s no definitive proof either way. A lightning bolt is just too powerful to be diffused by a small metal brush on the top of the mast.

But, frankly, their guess and your guess is as good as my guess. If it makes you feel better, it may be worth the price.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.


Sent from Mail for Windows 10

From: Tom Grass
Sent: Monday, December 14, 2020 12:23 PM
To: C320-List at catalina320.com
Subject: Re: [C320-list] Lightning

Thanks for all of the replies regarding lightning.  What are your opinions
regarding a lightning dissipator mounted to the top of the mast?

Tom Grass
Bucket List

On Mon, Dec 14, 2020 at 10:20 AM John morrison <sail-ability at sympatico.ca>
wrote:

> I read something awhile ago that Catalina made a deliberate decision not
> to electrically bond all of the metal components. It basically said that
> lightning in the order of a Brazilian V will do whatever it bloody well
> pleased. Bonding is expensive producing no benefits. This came up during my
> recent survey whereas the surveyor stated that all metal components needed
> to be bonded. I discussed the issue with him and he withdrew the
> requirement. I have two heavy jumper cables which I attach to the shrouds
> and then dangle in the water. Evidently it doesn’t help but it gives me
> peace of mind……..sort of.
> JohnM
> 1999#574
> > On Dec 13, 2020, at 11:39 AM, Jack Brennan <jackbrennan at bellsouth.net>
> wrote:
> >
> > Hi Tom:
> >
> > My 1998 320 has a thick cable bolted to the mast support and connected
> to a keel bolt. In theory, the mast is the lightning rod and the massive
> keel is the ground stake. However …
> >
> > Lightning is kazillion volts and basically does what it wants to. It
> might run straight down through the keel, or maybe it does a side flash to
> other metal such as the oven. We are lucky to have Marelon through hulls
> because they won’t attract side flashes and melt, the way bronze could.
> >
> > I live in Florida, the lightning capital of the world, and I have had
> two close brushes with lightning in 40 years of off and on sailing. That
> should tell you something about where it should be on your list of worries.
> >
> > In the first, I was in my 19-foot sailboat about three miles off Fort
> Lauderdale, making a late return at night from the Keys. I pulled down the
> sails and lit a cigarette (I smoked back then) while lightning bolts struck
> all around me for about 30 minutes. I could see them hitting the water, but
> none hit me. Scared the hell out of me.
> >
> > The second was about seven years ago. My wife and I were scrambling in
> as a summer thunderstorm arrived in Hillsboro Inlet from the Everglades. I
> was dropping the anchor in 30-knot gusts when a bolt struck about 40 yards
> from us in the harbor. It knocked out random electronics in my Bristol 30,
> but I didn’t feel anything.
> >
> > So my rules are take down the sails, anchor if you are in restricted
> waters, lock the wheel to protect the rudder, go below and stay away from
> metal. I also shut off the electricity and put all cellphones, computers,
> portable GPS’s, handheld radios, etc., in the oven.
> >
> > The reason for that is something called the Faraday Cage. Anything
> enclosed in metal won’t be affected by lightning. It’s why the 747 doesn’t
> go down when it is struck by lightning. If it does get bad, you have the
> ability to call for help.
> >
> > Hope this helps.
> >
> > Jack Brennan
> > Sonas, 1998 Catalina 320
> > Tierra Verde, Fl.
> > Dolphin Cruising Club of Tampa Bay
> >
> >
> >
> >
> >
> > Sent from Mail for Windows 10
> >
> > From: Tom Grass
> > Sent: Sunday, December 13, 2020 10:12 AM
> > To: C320-List at catalina320.com
> > Cc: Tracy Grass
> > Subject: [C320-list] Lightning
> >
> > Wondering about lightning protection on Catalina 320 boats?  I don't
> > believe they come grounded (mast to keel) from the factory - wondering
> what
> > the members of this forum have done in an attempt to minimize the impact
> of
> > a possible lightning strike?
> >
> > Also what is the collective opinion of installing a Forespar Performance
> > Products Forespar Lightning Master™ - Static Dissipater
> > on your mast?  We're planning on sailing down to the Chesapeake Bay and
> > perhaps to the Bahamas in 2021 - just preparing in advance.
> >
> > Thanks,
> >
> > Tom and Tracy Grass
> > Bucket List
> > 2008 Catalina 320 MK II
> >
>
>