In 1872, sailors found the Mary Celeste drifting in the Atlantic, still afloat with some sails up, but empty. Its small boat, navigation tools and papers were gone.
The missing items suggest they left on purpose, trading a floating ship for a small boat on the open ocean.
Why? Maybe fumes from its alcohol cargo made them fear an explosion, or the crew turned on their captain. No one knows; none was ever seen again.