Every other Friday, the Outside/In team answers a listener question about the natural world. This weeks question comes from Tyler in South Carolina.
"What is the significance of the color red being used with light houses?"
NHPR producer Marina Henke looked into it.
Transcript
This has been lightly edited for clarity.
Marina Henke: It may be tempting to think of lighthouses as stand-alone tourist attractions, perched on rocky outcrops, maybe flashing a lone light across the water. But 100 years ago, the federal U.S. Lighthouse Service maintained nearly 1,000 functioning lighthouses across the country.
Jeremy D'Entremont: They built enough lighthouses eventually so you were never out of sight of a lighthouse.
Marina Henke: Jeremy D’Entremont is a historian for the U.S. Lighthouse Society. And during this heyday of lighthouse navigation he described the resulting effect as a “light network” strung along the coast. Like our listener noted, it was a network with a whole lot of red.
Jeremy D'Entremont: Sankaty Headlight on Nantucket, White Shoal Light in Michigan. . . . On Cape Cod, Nauset Light is kind of an iconic lighthouse.
Marina Henke: Beyond making for dashing gift-shop keychains, the reason for this popular hue is two-fold. First is that the color red often helps lighthouses stay visible. To be seen, after all, is the primary purpose of a lighthouse.
Jeremy D'Entremont: I always tell people they’re kind of like the signposts of the sea.
Marina Henke: But these “sign posts of the sea” are only useful if sailors can spot them. At night, a lighthouse’s beam does the trick, but during the day that flash of a bulb can be pretty hard to spot, which means a lighthouse’s paint job actually matters a lot.
Jeremy D'Entremont: I should point out that in New England, most of our lighthouses are a very simple white, with black iron lanterns.
Marina Henke: Against the dull browns and grays of a New England coastline, white stands out. But, not always. Just like an outfit, sometimes a lighthouse benefits from a pop of red.
Jeremy D'Entremont: For instance, in Maine, West Quoddy Head Light at the easternmost point of the United States has red and white stripes. There's a pretty fair amount of snow up there. So the red shows up really well against the snow background.
Marina Henke: Red, it turns out, is a highly employed color in the nautical world. That’s because our eyes pick it up extraordinarily well — yes, against snow, but also water. The second reason for red’s popularity comes from a lighthouse’s need to be unique. With so many white lighthouses along the coast, sailors found that the structures could be hard to tell apart.
Jeremy D'Entremont: So they decided to give some lighthouses distinct paint schemes or "daymarks" as they’re known.
Marina Henke: These daymarks are the reason for the delightful variety in light house patterns that exist today: red checkers, red diamonds, black stripes. All these variations leave most lighthouses with their own unique fingerprint. They’re cataloged in a yearly report that the Coast Guard puts out called the U.S. Light List.
Today, lighthouses are often a backup to more high-tech instruments. But, it doesn’t mean these structures are without a purpose. After all, sometimes tech fails.
Jeremy D'Entremont: You know, people tell me all the time, they still like seeing that lighthouse . . . that actual physical confirmation of where they are.
Marina Henke: Whether it’s the stripes of West Quoddy or the thick band of Nauset Light, there’s a sailor out there who knows that red marking means they’re coming home.
If you’d like to submit a question to the Outside/In team, you can record it as a voice memo on your smartphone and send it to outsidein@nhpr.org. You can also leave a message on our hotline, 1-844-GO-OTTER.
