In other words, they were seeking to establish that it's not an island that once existed and has been submerged due to rising sea levels, it flat-out never exis

In other words, they were seeking to establish that it's not an island that once existed and has been submerged due to rising sea levels, it flat-out never existed. Or, y'know go out there to map the place to get better and more accurate maps. If it has an island that isn't there, it's not a good sign that your maps of the area are accurate.