What are the Odds?

Testing the claim that you're more likely to be struck by lightning than attacked by a shark

With a bit of luck, you won’t encounter either of these things in your lifetime.

One of the most baffling aspects of Mick Fanning’s recent encounter with a great white shark is the statistical improbability of it even happening in the first place. As surfers, we’re all familiar with the “you’re statistically more likely to be killed by lightning than attacked by a shark” argument (adding a touch of irony to Fanning’s nickname, “White Lightning”). However, examining how those odds are calculated may prove that, at least for surfers, being attacked by a shark is at least a bit more probable than we’re led to believe.

I’ve tried to debate with shark attack stat-spewers, explaining that every time I surf, I’m essentially dressing like a seal and splashing around in the ocean in a manner similar to a wounded animal. And, as a surfer, I’m doing that substantially more often than the average American enters the water. That’s like donning a suit of iron every time there’s a thunderstorm and climbing to the top of a tree. Sure, I might not get struck—but I am certainly upping the odds.

As a (very) amateur scientist, I set out to test my theory. I started by looking at how the statistics for death-by-shark versus death-by-lightning are actually calculated. 1 in 3,748,067 are the lifetime odds given for a shark fatality, compared to 1 in 79,746 for death by lighting, according to the Florida Museum of Natural History. This is problematic, as these numbers are derived from dividing the total U.S. population—not the total U.S. surfing population—by the number of annual deaths from shark attacks or lightning strikes, divided again by life expectancy.

The average American isn’t addicted to being in the ocean. But surfers are, so perhaps there’s a more accurate equation to predict these odds. Let’s start with the American population of surfers, once estimated by Matt Warshaw in an interview to be somewhere between 1.7 and 2.4 million (Warshaw cited figures collected by American Sports Data that classified a surfer as someone who rode at least one wave in a given year, though I’d bet the population of what most of us define as “being a surfer” is, in fact, much smaller). According to the FMNH, the average number of annual shark attack fatalities in the U.S. is one. So lets divide the surf population by annual shark attack deaths by life expectancy.

Here’s our new equation, using the original model:

U.S. surfing pop. (2,000,000) / annual shark attack fatalities in the U.S. (1) / American Life Expectancy (78)

This new equation sets the lifetime odds of surfer in the U.S. being the victim of a fatal shark attack  at 1 in 25,641, which seems much more realistic compared to the 1 in 3.7 million chance we are continually told. So, should we still be scared of a little electricity?

According to these calculations, a surfer in the U.S. is approximately 3 times more likely to be killed by a shark than by a lightning strike. And sure, just as a surfer is more at risk of shark attacks than the average citizen, an avid backpacker could argue they are more likely to be killed by lightning than somebody who spends all their time in Cleveland. The point of my theory though, is this. Yes, the odds of being attacked by a shark are low, but they are drastically increased for surfers.

(Ed. note: To answer your question, the chances of being attacked by a shark while being struck by lightning are somewhere around .0.0000000004891%. Side ed. note: We’re not statisticians.)