Faster-than-light (FTL) engines use a gravitational well to fold space in front of a ship, and lift space behind a ship. The ship then falls into the well, simultaneously being pushed by the wave behind. In essence it turns space-time into a large wave and the ship rides it through the galaxy. Although a ship travels faster than the speed of light, FTL drives are still considered slow. FTL ships can take up to three months to travel the same distance a COIL drive can in a day. Despite this, FTL drives are more popular on small ships that do not have to travel great distances. An FTL drive is smaller, does not require as much energy, is easier to navigate, and is more stable than COIL.