A University of West Florida study of three wrecks from Tristán de Luna y Arellano’s 1559 Florida expedition found unusually weak magnetic signatures, suggesting magnetometer surveys may miss other early colonial wrecks; researchers recommend more flexible search methods.
The wrecks—Emanuel Point I, II and III—were identified in 1992, 2006 and 2016. Divers found the third while excavating a nearby site, after probes registered a hard return.
At Emanuel Point III, researchers linked only about 9.1 pounds (4.15 kilograms) of iron to the anomaly. Small iron fasteners at EP II and III could be detected with a handheld gradiometer only from about 9 inches away. The weak signatures may reflect metal stripped after the ships sank or lost to corrosion over the centuries. Researchers recommend revisiting weak signals and combining magnetometers with close-range tools.
