Originally Posted by Vinny_HC

Overhead and underfoot are basically when the moon is perpendicular to the surface at the point where you are located. Overhead is when the moon is directly above you at the highest point in the sky (whether middle of the day or at night). When it is underfoot the moon is antipodal (opposite) side of the earth, but directly below you, so it would be directly "overhead" in the Indian Ocean while it was "underfoot" for you.