It is fairly universally known that Laird Hamilton has some pretty odd opinions and if you corner him in the front seat of his car and stick a camera in his face, some of them are bound to fall out of his mouth.

In this instance he was getting grilled by the rigorous investigative journalists at TMZ on the likelihood and causes of shark attacks and it didn’t take long for the worlds most famous waterman to drop a knowledge bomb.

“The biggest most common reason to be bit is a women with her period” he explained. “You know most people don’t event think about that, obviously if a woman has her period there’s a certain amount of blood in the water.” Before clarifying his point with an air tight analogy: “It’s kind of like running around with a lightning rod and wondering why you get struck by lightening”.

Although we imagine Laird is right that most people, including us, have never really thought about it before, there are a few instances on the world wide web where the question has been posed to experts, and it turns out almost all of them staunchly disagree with Laird:

“The amount of blood that is produced during menstruation is so small that it becomes background with all of the other components that are in the water,” replied Dr. Chris Lowe, head of California State University, Long Beach’s Shark Lab when the question was posed to him. “It would be very difficult for a shark to localize that.”

According to Dr. Steve Kajiura of Florida Atlantic University’s Shark Lab ., sharks are far more interested in the smell of amino acids than blood. This is affirmed by a study done in the late 60s by H. David Baldridge, where several bodily fluids, including menstrual blood, were introduced to captive sharks in ocean pens to see if any would cause a feeding frenzy. Apparently the only one that did was abdominal cavity fluid (the funding ran out before Baldridge and his pals could figure out why though).

Although sharks are attracted to the blood of other marine animals, Baldridge pointed out that our blood is very different to “a sea otter’s blood or cetacean blood” because “our blood is from a terrestrial environment.” Accordingly he theorised that the scent of human blood doesn’t send the message to sharks that there is a wounded animal fit for a meal nearby.

It’s possible that Laird is getting sharks confused with Komodo dragons, which if the guides on the island of Komodo are to be believed, are attracted to period blood, however that’s about as much as we can defend what seems like an otherwise bogus and irresponsible claim.