| Fiction over fact|
|How it didn't happen|
| Some dare call it|
|What THEY don't want|
you to know!
A phantom island is an island that was or is believed to exist, but does not actually exist. Phantom islands have appeared on maps during the entire history of cartography. Legendary islands like Atlantis are not usually considered phantom islands, as their status is mythical, rather than due to errors in exploration or map making.
Causes for reports
Reports of phantom islands have several causes. A common explanation is the misidentification of a genuine island. Pepys Island, for example, was in reality the Falkland Islands. Sometimes fog banks, icebergs or optical illusions are mistaken for real islands. Sometimes islands that existed in the past have disappeared due to volcanic eruptions (such as one Greek island), tectonic activity, sea level rise, or erosion. Some islands are just made up, for fraudulent or political reasons.
Phantom islands in pseudohistory
Occasionally phantom islands get a second life in theories claiming that islands or continents were discovered earlier than the date that is commonly accepted. This is especially common for islands in the Northern Atlantic: maps depicting Antillia, Estotiland, Frisland, Bacalhau, Saint Brendan's Island, Brasil and Greater Ireland have all at one time or another been considered evidence for a pre-1492 discovery of the Americas. Occasionally such a theory may be true; after all, it has now been decisively proven that Vinland, which was discovered and named by Vikings, is Newfoundland. But more often than not such theories are way off and ought to be considered as pseudohistory.
A well known example is in Gavin Menzies' 1421: The Year China Discovered the World. Menzies uses a 1455 Portuguese map that depict the islands of "Antillia" and "Satanzes" as evidence that the Chinese reached the Americas in 1421. Menzies identifies these islands as Puerto Rico and Guadaloupe, despite the fact that Puerto Rico runs from west to east and not from north to south like Antillia, that both islands are depicted at most 2000 kilometers away from Europe, half the distance of Puerto Rico and Guadaloupe, and that the relative position of Antillia and Satanzes do not match those of Puerto Rico and Guadalupe.
Phantom islands today
Phantom islands are usually considered something of the past, but even today there are islands of which the existence is not satisfactorily defined.
The islands Maria-Theresa and Ernest‑Legouvé, purportedly located south of the Tuamotu islands of French Polynesia, spotted in 1843 and 1902 respectively. It is now generally accepted that both islands do not actually exist, but they still appear on some maps. Maria-Theresa is noted for its appearance in Jules Verne's novels In Search of the Castaways and The Mysterious Island. A 1966 radio broadcast from Maria-Theresa was later revealed to be a hoax.
Other phantom islands in the same area are Wachusett Reef, Jupiter Reef and Rangitiki Reef. Wachusett Reef appears in the 2005 edition of the National Geographic Atlas of the World. Another example is Kiribati's Filippo Reef, which probably doesn't exist, but is nonetheless mentioned in the same edition of National Geographic's Atlas as well on Wikipedia.
Perhaps the most controversial contemporary example is Bermeja. Bermeja is supposedly located in the Gulf of Mexico, north of Yucatán, at 22°33′N 91°22′W. It has been reported on maps since the 17th century, but it has not been sighted since the 19th century, does not appear on even the oldest satellite photographs and a survey from the Mexican Marine Secretariat in 1997 did not manage to find the island. The sea around Bermeja's supposed location is 40 meters deep. Bermeja's "disappearance" is controversial, since its existence is relevant for determining the maritime border between Mexico and the United States in the oil-rich Gulf of Mexico. The case has spawned a conspiracy theory in Mexico, which claims that the CIA dynamited the island in the 1970s in an attempt to rob Mexico of part of its oil reserves. This theory has been defended by several Mexican politicians and has been reported in various media outlets.
According to the Mexican government, it is likely that the island disappeared either because of sea level rise or because of tectonic events. For the Clinton-Zedillo treaty of 2000, which fixed the maritime borders between Mexico and the United States, the island was considered not to exist. If it had existed, the border would have been 100 nautical miles north of its current location.