By definition (assuming that the entire surface can be classified as either "land" or "ocean"), the two hemispheres do not overlap.
One determination places the centre of the land hemisphere at 47°13′N 1°32′W / 47.217°N 1.533°W / 47.217; -1.533 (in the city of Nantes, France).
An alternative assignment determines the centre of the land hemisphere to be at 47°24′42″N 2°37′15″W / 47.411667°N 2.620833°W / 47.411667; -2.620833 (in Île Dumet [fr] near Piriac-sur-Mer, France).
[2][3] The centre of the sea hemisphere is located at 47°24′42″S 177°22′45″E / 47.411667°S 177.379167°E / -47.411667; 177.379167 (near New Zealand's Bounty Islands in the Pacific Ocean).
Africa, Europe, and North America are solely within the land hemisphere.