Vanishing Islands - Google Maps

Sandy Island in Google Maps - It's the "grain of rice" at the northwest corner

The story of Sandy Island, the mysterious Coral Sea island that may or may not exist, has been all over the news recently. To make a long story short, a group of researchers in studying plate tectonics decided to stop by Sandy Island recently to check it out. The island had piqued their interest because it was not on their navigation charts of the area, but popped up on Google Maps and Google Earth. 

Sandy Island in Google Earth  - It's the black hole on the left 

After what I can only imagine was a drunken night of sailing they arrived at the "island", which turned out to be nothing more than the open sea. A quick Google search of the subject will return a long list of results attempting to explain why the island displeasure or never even existed. Really, I don't care. The important lesson here isn't what happened, but to understand that maps, even by Google, are never perfect. They are influenced by people, culture, the past, and technology.

I wonder how many other islands are mapped but don't exist. More importantly, how many might exist that have never been mapped?