These Colonial Shipwrecks Vanished for 400 Years. Countless More May Be Hiding Near You.

3 min readTristán de Luna’s 1559 Pensacola settlement predated Jamestown by 48 years but collapsed after two years, when a hurricane destroyed ships and supplies.Three shipwrecks from Luna’s expedition went undiscovered for over 400 years because they produced unusually weak magnetic signatures that conventional detection methods were designed to overlook.A new study suggests archeologists may have missed countless early colonial shipwrecks by applying rigid detection standards, raising questions about how incomplete our understanding of this maritime era truly is.In August 1559, Tristán de Luna y Arellano landed in what’s now Pensacola, Florida, anchoring his vessels near a bluff known as Emanuel Point. His expedition brought 1,500 soldiers, colonists, and enslaved people from Veracruz, Mexico, aboard 11 ships to establish the Luna settlement. Predating Jamestown by 48 years, the settlement only lasted two years, and during that time it was battered relentlessly by the forces of nature. In fact, just a month after the settlers’ arrival, a mighty hurricane swept through and destroyed most of their ships, taking with it most of their supplies (the ships had been used as a sort of floating warehouse).It would take over 400 years for some of those sunken ships to be discovered. A new study looked at why, and found that archeologists have been searching for shipwrecks all wrong.The study, written by William J. Wilson and Gregory D. Cook of the University of West Florida and published in Archaeological Prospection, looks at three shipwrecks from the expedition: Emanuel Point I, found in 1992; Emanuel Point II, found in 2006; and Emanuel Point III, found in 2016; all were discovered near each other.EP III turned up by accident. Study co-author Gregory Cook was excavating EP II when his divers hit “an anomaly” that turned out to be a third ship.“Magnetometers detect anomalies in Earth’s magnetic field, caused by the presence of iron, which is common on shipwreck sites,” Cook said, according to WFUF reporting at the time. “We trained dive teams to conduct circle searches with probes or hand-held metal detectors. Almost immediately on this day, divers surfaced and said they could feel a hard return – or ‘stones’ – with their probes.”The study Cook co-authored looks at the anomaly detection method that ultimately found the three Emanuel Point wrecks to explain why it may have taken so long to discover them, and why many other older shipwrecks may still be going undetected. The problem appears to be a “one-size-fits-all” approach to magnetometers.“Magnetometers have been utilized to find shipwreck sites in submerged contexts for at least the past five decades,” the study notes. The reason is that the degraded condition of ship timbers above the seafloor makes acoustic search methods during geophysical surveys challenging. But when the researchers measured the anomalies produced by the three EP wrecks, they found them to be surprisingly “magnetically quiet,” so conventional approaches to detection would likely have overlooked them.“The Emanuel Point shipwrecks do not necessarily fit the magnetic anomaly criteria often used for locating shipwrecks,” the study notes. The shipwrecks largely lack the magnetically detectable iron that would cause them to be noticed by conventional survey standards. EP III only had around 4.15kg of iron associated with its anomaly, and both EP II and EP III sported small iron fasteners only detectable by handheld gradiometer at around 9 inches’ distance.These wrecks likely featured more iron centuries ago when they sailed, but for one reason or another, that amount diminished over time. The study speculates that some iron may been stripped shortly after the vessel sank, based on an archival letter that mentioned building “a frigate and a small foist from the wood and nails of the ships which sank.” More iron may have been wiped away due to centuries of corrosion. Whatever the reason, the lack of iron in the wrecks today meant that the EP shipwrecks were easy to overlook with conventional detection criteria.The authors recommend “survey designs that reflect the types of resources likely to be present” when searching for shipwrecks instead of assuming that all shipwrecks offer the same detectable materials. But that seemingly sensible recommendation also conveys an idea that should shake even the most casual consumer of underwater archeology content: our entire understanding of early colonial shipwrecks may be inaccurate.“The characteristics of the Emanuel Point shipwreck anomalies do not appear to be common across other early colonial shipwrecks in North America,” the study notes. “Whether or not that is due to much lower rates of detection is unclear at this time.”In other words, maybe the long-undetected Emanuel Point wrecks weren’t unusually hard to find. Instead, they may actually be typical of an era of maritime travel that we’ve simply failed to discover? How many other shipwrecks are still hiding in proverbial plain sight, but remain overlooked because we have the wrong idea of how a “typical” shipwreck should be detected?Michale Natale is a News Editor for the Hearst Enthusiast Group. As a writer and researcher, he has produced written and audio-visual content for more than fifteen years, spanning historical periods from the dawn of early man to the Golden Age of Hollywood. His stories for the Enthusiast Group have involved coordinating with organizations like the National Parks Service and the Secret Service, and travelling to notable historical sites and archaeological digs, from excavations of America’ earliest colonies to the former homes of Edgar Allan Poe.