best bet is to use the sw monsoon that blows may till october north of the equator to get to
malaysia,then
work your way down through
indonesia till you can turn right for darwin.
alternatively if you want to get to perth leave seyshells in sept-oct for richards bay,head down to port elizabeth,then
head down to about 35-40 s where you will find westerlies,best done in nov dec-jan