Grey Town Noises

From about 1867-1871, there were reports of a strange noise reverberating through iron-hulled ships outside of Grey Town in Nicaragua. The noise did not affect wood-hulled ships, only those made of iron, and consisted of a loud, long, high-pitched, steady vibration. It was “musical” in its likeness, and its source could not be determined. One captain said that the sound had a distinct ¾ time signature like a waltz that turned his ship’s hull into a “great musical sounding board.” The source of the vibrations is still undetermined to this day, and no mention of anything similar around Grey Town has been reported since 1871.