If you visit a coffee shop at the Ferry Building Marketplace in San Francisco, California you’ll see a strange sign.
“No bananas on board,” the sign reads. It features a cheerful graphic of a bunch of bananas crossed out by a red circle.
Why on earth would bananas be banned aboard the Bay Area’s ferry fleet? It turns out the ban is part of a mysterious maritime curse that goes back centuries.
Indigenous Knowledge and Modern Superstition
According to Snopes, a website that researches urban legends, the prohibition on bananas aboard ships has existed for hundreds of years.
Its origins are mysterious, but there are several possible reasons for the superstition. Banana bunches sometimes conceal spiders or bacteria, neither of which mariners of yore wanted aboard their vessels.
Indigenous people also many have recognized that carrying bananas between islands risked spreading banana diseases that could wipe out whole farms. The prohibition may have started as a way to keep diseases and pests contained.
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A Scientific Reason
There’s another more science-based reason for ancient mariners’ fear of bananas, too.
Bananas emit ethylene gas as they ripen. This causes other fruits around them to also ripen faster. That’s why if you want to ripen a green tomato or underripe apple, you can place it in a bag with a banana.
It’s possible that mariners placed bananas in the holds of their ships alongside other fruits. The ethylene gas from the bananas would have caused the other fruits to ripen too quickly and spoil before the ship reached its destination.
The sailors may have concluded that bananas are bad luck, or even cursed. They wouldn’t have understood the science of ripening and ethylene gas, assumed that a banana curse of some kind was responsible, and banned the fruit from future shipments.
Still Here Today, Including in SF
Whatever the origins, the myth appears to have stuck around. The New York Times quotes a modern fishing boat captain as saying that if a customer wears a Banana Republic brand shirt on a fishing charter, a staff member will use a knife to cut off the logo before the customer is allowed on board.
That’s how deep this nautical myth goes.
Apparently, this myth is ubiquitous enough in the maritime world that it’s even present here in the usually un-superstitious Bay Area.
So what are the risks involved?
I asked the San Francisco Bay Ferry what happens if you bring a banana aboard one of their vessels.
Their response? A cryptic “You don’t want to know. 👀”