When ocean surveyor Captain Sir Frederick Evans became the new chief hydrographer to the Royal Navy in the 1870s, he was tasked with charting the Pacific Ocean, which for more than 400 years had been filling up with "phantom islands," reports Intelligent Life magazine. That is, islands that existed on paper but not in reality—based on "false sightings, hopeful imaginings, brazen inventions, icebergs, pumice rafts, navigational errors," and so forth. Having spent half his life at sea, and having developed the standard treatise on magnetic deviation in iron ships, Evans was uniquely qualified to take his red ink to paper to create Pacific Ocean Chart 2683. Evans would ultimately erase 123 islands from the maps of the Pacific, and while his scientific mind and rich naval experience no doubt helped, it turns out he erased three too many—and let a few non-existent islands slip under the radar.
Morrell Island, for instance, continued to appear to the northwest of Hawaii on various maps until the 1920s, and even on Lufthansa's globes as recently as the 1980s, while a pair of islands, Los Buenos Jardines, were written up in 1529, always questioned, and not erased until the 1970s. Even Sandy Island, first reported by a whaling ship in 1876 shortly after Evans retired his red pen, and winding up on Google Earth, wasn't un-found until 2012, when a survey ship trying to check it out ran into nothing but deep waters. Its location was far enough from shipping lanes that the error had gone unchecked for more than a century, notes Conde Nast Traveler. (This 19-year-old cartographer tracks ISIS from his bedroom in Amsterdam.)