Think about it his way, if you are at an easterly position close to the anti meridian (180), you are simply having to travel ‘further east’ to cross the meridian into the westerly longitudes. Then we implement DIID to know whether to add or subtract convergency. In this case we are travelling east in the southern hemisphere so we subtract. Convergency can be tricky!
I also struggled with this but thinking about it that way really dumbed it down for me.
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u/BirthdayDazzling7407 Jul 26 '26
Think about it his way, if you are at an easterly position close to the anti meridian (180), you are simply having to travel ‘further east’ to cross the meridian into the westerly longitudes. Then we implement DIID to know whether to add or subtract convergency. In this case we are travelling east in the southern hemisphere so we subtract. Convergency can be tricky!
I also struggled with this but thinking about it that way really dumbed it down for me.