The following report comes from the 19th Century - 1830, to be precise.
The British navy ship Rob Roy was sailing towards St Helena, an island in the middle of the Atlantic which has the distinction of not being near anywhere else. At about 5p.m. the huge head of a serpentine creature rose out of the water to the fore of the ship, to the great astonishment of those aboard. This creature may have been as surprised as the jolly tars concerned - it certainly seemed somewhat nonplussed. Captain James Stockdale was later to write that twenty foot snakes he had killed would have fitted into the animal's mouth. He estimated the animal to be about 129 feet in length. It had a fin between its shoulders. Captain Stockdale in his report evinced a desire never to meet the creature again.