Passengers and crew on a Royal Mail steamer ship heard strange noises while off the coast of Nicaragua in March 1867. Captain Charles Dennehy of the R.M.S. Shannon also noted this in May 1870. The ships were anchored near Greytown in the Caribbean Sea. The noises sounded like loud, high-pitched metallic vibrations that travelled through the hull of the ship. It continued for about two hours. Strangely, the noise had been heard only on board the iron steamers, not the wooden ones. Speculation ranged from Sciaenidae, fish known for its ‘drumming’, sharks, manatees, musical fish, changing currents. There was no mention of it after 1871.
The Greytown Noises
