pair of lox, a 5% chance of getting hit = a 95% of NOT getting hit.

A 5% chance of getting hit = .95 times .95 = a 90% of NOT getting hit even
once EITHER time in two tries.

a 5% chance of gettting hit = .95 times .95 times .95 times .95 = 81% of NOT
getting hit even once in FOUR tries.

by 8 tries the chance of NOT getting hit is only about 2 out of 3, by 14 tries
there is a better than even chance of being hit **AT LEAST ONCE**. by 30
tries, the chances of being hit at least once are 4 out of 5. by 50 tries,
chances of being hit at least once are greater than 15 out of 16. by 70 tries,
32 out of 33. by 90 tries, greater than 99 out of a 100.

that oak tree standing on the hill would be toothpicks by the end of the second
season.

Understand that in central Florida they receive more than 100 electrical storms
each year. a 5% chance of getting struck would mean central Florida has never
had trees.



How do you define "effective" area?
Your equation assumes that any lightning within the effective area of your
boat will strike your boat. If that were the case I'd be very afraid.

"Parallax" wrote in message
om...
Out of curiosity, I did a quick back of the envelope estimate of the
probability of a lone sailboat getting hit by lightning in a
thunderstorm.

...

I found a web site that gave a strike rate of about .5 strikes/km^2/yr
but they did not say where they measured this. However, this means
that a lone sailboat with a mast 17 m tall would have a .35% chance
each yr of getting struck. This is an ideal situation though and may
not address the situation of a sailboat under a thunderstorm where the
strike rate/km^2 is hundreds of times higher. Because I know that the
strike rate in Fl is much higher than average, I'd want to double the
strike rate they give to be about 1/km^2/yr. This gives about a .7%
chance each yr of getting hit. Again, this does NOT address the
situation where you know the strike rate is much higer than average
(sitting under a storm). Based on math and observed strike rate, I
still think my estimate is good.