Water and Lightning Strikes

Uh, Tampa is not on the ocean. That person was either swimming in Tampa Bay or the Gulf of Mexico…


Welcome to the Straight Dope, **Lily2 **. It’s customary to include a link to the staff report when you start a thread about one. Like this:
Link to the staff report: http://www.straightdope.com/mailbag/mlightning.html

It happened near Clearwater Beach, on the Gulf, according to Adam Emerson,
“Swimmers Hit By Lightning On The Mend,” Tampa Tribune, July 26, 2005

Does anybody really think that the Gulf of Mexico isn’t part of the Atlantic Ocean? Is there a magical barrier somewhere that no one’s told me about?

Or Tampa Bay, for that matter.

I am skeptical that swimming during a lightning storm is “relatively dangerous.” Jack Williams (the USA Today weather editor you quote) cites no sources, and you could only come up with two anecdotal cases – worldwide – over several years as examples. And neither example had fatalities. Dangerous? Swimming during a storm is probably less dangerous than riding a motorcycle for the same length of time. Statistically, danger from lightning at the beach pales in comparison to danger from tsunami. (Averaging over 10,000 fatalities per year worldwide.)

There were plenty more.

The earliest one I happened to find was reported at “Father and Son Killed: Struck by Lightning While Swimming From a Capsized Boat at Stamford,” New York Times, September 2, 1895

All of the cases I mentioned were described in newspaper articles. Are you suggesting these people really weren’t struck by lightning? Or that they weren’t swimming at the time?

Great report, GFactor - just the right mix of informative facts and insouciant commentary!


I guess it depends on what is meant by “relatively dangerous.” According to the government .pdf Gfactor linked to, there were only 38 lightning fatalities in 2005 (unless I’ve misread said .pdf.)

In all of 2005 not a single person died from a lightning strike while in the water, and only three died while in boats (out of the total of 38 lightning fatalities that year.)

I’d argue that the more normal hazards of swimming (like drowning) are way more dangerous than the risk of getting killed by lightning while swimming.

So sure, it might be “relatively dangerous” but only if we’re comparing swimming in a thunderstorm to something that is in and of itself extremely safe.

I do agree with the general idea that swimming during a t-storm isn’t really all that dangerous at all–at least not because of the lightning. I would imagine your risk of drowning goes up a good bit when swimming in such weather.

On what would you base your opinion? If a million people are swimming at a given moment on a clear day, how many drown? Not many, I’d suppose, not as a percentage of the total population engaging in the activity. Now, how large a population would you have of people swimming in a thunderstorm? Not very big, I’ll wager. Mainly because common sense would tell the vast majority of people to get out of the water.

That’s what we’re comparing.

Eh? The Gulf of Mexico is part of Tampa Bay? [/Gracie Allen]

I’d be surprised if we had any accurate totals for “number of people swimming” in any given day. That’s something that would be very hard to quantify, I would think.

And I never said “we” weren’t, as I said, relatively dangerous is correct if you’re comparing it to something people consider extremely safe.

In the case of swimming in a thunderstorm, it is (based on the evidence) relatively safe compared to tons of stuff people do every single day so I’m not really sure people should concern themselves about it–even if it is “relatively dangerous” when compared to stuff that is extremely safe.

And 308 injuries. Still not a huge number, I agree. Of course, we need to take into account:

  1. Those are U.S. Figures only.
  2. Some experts claim they are underreported
  3. 40% of the strikes are lumped into the “Various Other and Unknown” category.
  4. It probably makes more sense to look at the numbers over a period of years than the last one that happens to be available.
    Nevertheless, even if we accept the numbers suggested by Rakove & Unman in Lightning: Physics and Effects (2003): 100 deaths/1000 injuries annually in the U.S., that’s still way less than the number of drownings. http://www.nsc.org/lrs/statinfo/odds.htm (3,306 in 2003, just for accidental non-boat-related). Your annual odds of accidental drowning in 2003 were 1/87,976 and your lifetime odds were 1/1,134.

Odds of death by lightning in the same year were 1/6,188,298 and the lifetime odds were 1/79,746.

But the questioner assumes lightning is striking nearby, which increases the odds substantially.

Here are my references, by the way:
“4 Swimmers Struck by Lightning in Chiba Prefecture,” Kyodo World News Service, July 31, 2005

“2005 Annual Summaries: Flood/Flash Flood, Lightning, Tornado, Hurricane,” National Oceanic and Atmospheric Administration: http://www.ncdc.noaa.gov/oa/climate/sd/annsum2005.pdf

Bragaw, Matthew, Lightning Safety, Jetstream: An Online School for Weather, National Weather Service, September 17, 2004: http://www.srh.noaa.gov/jetstream/lightning/lightning_safety.htm

Cooper, Mary Ann, Lightning Injury Research Program: http://www.uic.edu/labs/lightninginjury/index.htm

Curran, Brian, et al., “Lightning Casualties and Damages in the United States from 1959 to 1994,” Journal of Climate, Volume 13, Issue 19 (October 2000): http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0442(2000)013<3448%3ALCADIT>2.0.CO%3B2

Curran, Brian & Holle, Ronald, "
Lightning Fatalities, Injuries, and Damage Reports From 1959-1994: http://www.nssl.noaa.gov/papers/techmemos/NWS-SR-193/techmemo-sr193.html

“Doctor Warns Against Using iPods in a Lightning Storm,” The Boston Globe, July 12, 2007: http://www.boston.com/business/globe/articles/2007/07/12/doctor_warns_against_using_ipods_in_a_lightning_storm/

Emerson, Adam, “Swimmers Hit By Lightning On The Mend,” Tampa Tribune, Jul 26, 2005. pg. 1

“Father and Son Killed: Struck by Lightning While Swimming From a Capsized Boat at Stamford,” New York Times, September 2, 1895, pg. 1

Gurevich, Alexander & Zybin, Kirill, “Runaway Breakdown and the Mysteries of Lightning,” Physics Today, May 2005, p. 37: http://www.phy.olemiss.edu/~jgladden/phys510/spring06/Gurevich.pdf

Holle, Ronald, et al., “U.S. Lightning Deaths, Injuries, and Damages in the 1890s Compared to 1990s,” NOAA Technical Memorandum OAR NSSL-106 (2001): http://www.nssl.noaa.gov/papers/techmemos/NSSL-106/

Miller, Craig, “Maps” Help Reveal How Lightning Strikes, NationalGeographic.com, September 25, 2002: http://news.nationalgeographic.com/news/2003/05/0522_030522_lightning.html

National Lightning Safety Institute, 35 Years of Lightning Deaths and Injuries: http://www.lightningsafety.com/nlsi_lls/35_years_injuries.html

National Weather Service, Lightning Safety Program: http://www.lightningsafety.noaa.gov/index.htm

Nave, Carl, Hyperphysics: Lightning: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/lightning2.html

Nova scienceNOW: Lightning, October 18, 2005: http://www.pbs.org/wgbh/nova/sciencenow/3214/02.html

Stanford Linear Accelerator Virtual Vistor Center: High Energy Cosmic Rays and the Atmosphere: http://www2.slac.stanford.edu/vvc/cosmicrays/cratmos.html

Walsh, Katie, et al., “National Athletic Trainers’ Association Position Statement: Lightning Safety for Athletics and Recreation,” Journal of Athletic Training 35(4) 471 (2000): http://www.nata.org/jat/readers/archives/jt0400/jt040000471p.pdf

Weiner, Nancy,
Experts Divided on What Attracts Lightning Some Say Electronic Devices Are Dangerous, Others Disagree, ABC.com, July 12, 2006: http://www.abcnews.go.com/GMA/Weather/story?id=2181843

Woods, Judith, “Thunder and Lightning are Very Frightening,” Telegraph.co.uk, 26/07/2006: http://www.telegraph.co.uk/health/main.jhtml?xml=/health/2006/07/26/hlightning26.xml

Those doctors are morons.

No question.

From the National Weather Service Site linked in GFactor’s excellent report.

I agree that lightning is dangerous, but aren’t the histrionics a little over-the-top?

Yes. It’s a bit heavy-handed.

And I’m saddened that nobody has pointed out this band name of an article:

Gurevich, Alexander & Zybin, Kirill, “Runaway Breakdown and the Mysteries of Lightning,” Physics Today, May 2005, p. 37: http://www.phy.olemiss.edu/~jgladden/phys510/spring06/Gurevich.pdf

And I have to wonder what had happened to the poor lighting that it was convalescing. Didn’t those swimmers know that an injured lightning bolt is extremely dangerous and may strike without warning?