Frogwatch wrote:
On Jun 3, 12:13 pm, wrote:
On Wed, 3 Jun 2009 05:07:03 -0700 (PDT), wrote:
On Jun 3, 1:50 am, wrote:
On Tue, 2 Jun 2009 21:12:38 -0700 (PDT), Tim
wrote:
OK, hypothetical, but my quesiton is how do you handle being caught in
a lightening storm in a boat.
I have two fiberglass boats an 18' and a 23'.
18 has an enclosed bow, and the 23 a small cuddie. basicly a bigger
enclosed bow.
Where I boat is Lake Carlyle, and it's about 10 mi. long and about 3
mi. wide. Now 'pop-up' showers arn't uncommon this time of year, but
sometimes that little sprinkle can turn into a lightening storm while
the boater is unawares. So while being caught in the rain. the bilge
[s] are on, and you're headed in. the baot is wet.. you're wet. what
is the concern about lightening?
I'm thinking at least sit still and everybody head under the
enclosures. until at least the lightning quits.
What say ye?
We have thunderstorms all the time and most of us in open boats worry
about getting hit by lightning but I haven't really heard any stories
about it happening.
The real trick is to be able to read the clouds and try to see them
coming in time to get to a safe place to wait it out.
If you do get caught in it get as low in the boat as possible and away
from the T top. Sailboat guys probably have tips about grounding since
that mast is a pretty attractive target.
The real trick is to be able to read the clouds
Or buy a hand held Barometer......
If you only went out when there was a rising barometer you wouldn't
get away from the dock around here in the summer.

One thought about "blue sky" lightning, be sure to look up!

There are lots of times here in the sub-tropics where there will be
blue sky and sunshine all around and if you looked straight up you
would see a big white puffy cloud. It might be a tower 15,000 feet
tall.
Radar can be deceiving too. Until it starts raining, these clouds
don't really look that bad on radar. That can be a pretty sudden
occurrence. These are the kind of storms Florida is famous for where
one guy can get an inch of rain in 15 minutes and the guy on the block
over doesn't get a drop.

Having had waaaaay too much experience with lightning, I tend to
obsess over it. Living in N. Florida and being both a sailor and
powerboater I have developed strategies for both. Your best strategy
is avoidance of thunderstorms.
If you cannot avoid them, here is what I do:

Sailboat. Disconnect VHF and GPS from power AND antennas so they will
work after a strike. Get passengers below decks so the wet decks and
hull can form a "Faraday Cage" for them and minimize effects on them.
Make sure nobody goes near metal stuff including the sink or the mast
on a keel stepped mast boat.
I drop my sails long before the storm hits and have my engine running
and attempt to power into the wind. if it gets too strong I turn and
run with the wind. Make sure everything is bonded to the engine shaft
and hope the prop will dissipate a strike.
I'd rather be at anchor during such a storm and I have a 2' x2' copper
sheet soldered and clamped to a 00 guage tinned copper braided cable
that clips to the mast as high as I can reach with another lead going
to the shroud at the edge of the deck. All of this should give me a
"cone of protection". I crouch as low as possible.

Powerboat (outboard): I run like hell back toward shore. Beach the
boat if necessary because I want trees near shore to offer a better
strike path than me, but stay on the boat. IF necessary, I anchor. I
also have a length of OO tinned braided cable I attach to my danforth
anchor that I drop overboard with anchor line attached so it hangs in
the water (Yes, I carry two anchors on my 20' boat) so the anchors
area will dissipate the current of a strike. Lower the VHF antenna
and disconnect the VHF from power and antenna. Crouch low in boat
under RAISED bimini. The bimini is grounded and helps form a Faraday
cage. Do not touch the wheel or throttle unless necessary. Stand one
one foot or keep feet together, SERIOUSLY. This avoids current using
your torso as a conduction path from one place on the hull to another,
your body is a better conductor than the wet fiberglass.



Nice to hear from you again, Dr. Emmett Brown.