'But it is not enough, because the Earth is round.'

'Had the Earth been flat, a total of three satellites would have been enough to provide this information to everyone on Earth,' Keijer said. GPS relies on a network of dozens of satellites orbiting thousands of miles above Earth signals from the satellites beam down to the receiver inside of a GPS device, and at least three satellites are required to pinpoint a precise position because of Earth's curvature, Keijer explained. There's just one catch: Navigational charts and systems that guide cruise ships and other vessels around Earth's oceans are all based on the principle of a round Earth, Henk Keijer, a former cruise ship captain with 23 years of experience, told The Guardian. But in diagrams shared on the FES website, the planet appears as a pancake-like disk with the North Pole smack in the center and an edge 'surrounded on all sides by an ice wall that holds the oceans back.' This ice wall - thought by some flat-Earthers to be Antarctica - is the destination of the promised FEIC cruise.

Flat earth society globe