[Paddlewise] Carbon Fiber Paddles and Lightning?

 "PeterO" <rebyl_kayak_at_iprimus.com.au> asked:

>> Can anyone tell me if there is any truth to the story I hear over and over
again that carbon paddles attract lightning more than fiberglass? I've never
understood how this can be so as I shouldn't have thoght the carbon fibres
formed a continuous conducting path. >>

This issue has been raised before.  The bottom line is that the voltages
involved in lightning are so enormous our "normal" thinking about what forms
a conductor and what does not needs to be thoroughly rearranged.

Here's my scan:

1. Lightning voltage is so great it ionizes and forms a glowing gaseous
plasma of whatever it contacts, forming good conductors of __anything__:
tree limbs, rocks, pencils, finger tips, iron rods, paddle surfaces, you name
it.  They all conduct current __at the voltage of a lightning strike__. Any
object denser than the surrounding air raised as a lightning rod will be a
"conductor", because it is likely to be wet during a lightning storm, and the
water on its surface is "conductive"  __at the impulse voltages of
lightning__, which are millions of volts.  In short, once struck, it makes
little difference what you are holding, although metal objects in the hand
lead to "hot spots" and localized burning, irrespective of whether cardiac
arrest has already killed you.

2.  A "good conductor" in the context of "low" voltage (<100 volts, say) such
as metals, carbon fibers, and the like, raised as a lightning rod, will be
__at greater risk__ to be struck by lightning,  __because it raises the
electrical potential at that point__.  In conversational parlance, it
"attracts lightning to it."  In other words, in a forest of sticks all at the
same height pointing to the sky, the lone stick coated (or made of) metal
will almost certainly be the one struck.

So how does this translate for Peter's question?  How about this:

If Peter extends his paddle upwards, by intention or otherwise, it matters
little whether it is made of wood, fiberglass/epoxy, or carbon fiber, as long
as his "lightning rod" is the only object sticking up above the water in the
near vicinity.  His paddle shaft is likely to be what gets struck.

If Peter extends his carbon fiber paddle up in a horde of paddlers also
extending their paddles upward, the rest of whom are equipped with much less
"conductive" paddles (in the low voltage sense), then the electric potential
at Peter will be somewhat greater, and Peter is very likely to be the one
struck ... if lightning strikes in the vicinity.  If Peter were to paddle
with a highly conductive paddle (metal shaft and metal blades), then the
chance he will be struck goes up quite a bit, because the low-voltage
conductivity of metals is a lot higher than carbon fiber, raising the
electrical potential on Peter's shaft.

Carbon fiber is much less conductive (in the low voltage sense) than metals,
and a little more conductive than epoxy./glass so there is a slightly greater
risk to use a carbon fiber paddle.

The lessons in this might be:

1. Don't paddle when lighning is about; choice of paddle shaft type makes
almost no difference, unless you can keep your paddle shaft and blades dry.
2. If you are forced to paddle in a lightning storm, keep a low profile and a
low stroke.
3. A good preventative might be to bring along a "friend" equipped with a
metal shafted paddle, and to paddle near him ... but not __too__ close!
[grin]

(P.S.:  A key concept here is what forms a higher electrical potential -- 
those who wish to pursue that might do a Google search on same and pursue how
charged clouds (and earth) induce changes in charge distribution and hence in
electrical potential.  Or, we could just skip it and head out for another
ale!)

--
Dave Kruger
Astoria, OR

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