More important than spelling south...is knowing where it is...and here is a trick that might save your life...and good reason to not use a digital watch...
Hold your watch flat like a sun dial...point the hour hand at the sun...and no matter where you are, or what time it is, or what the current magnetic deviation is...Half Way Between the Hour Hand and Noon is due South exactly...
If you are south of Lat 0.0.00...the same will find North for you...
Stay the course and know where your going....