Yep, end of the strongest Sou' Easters and before the cyclone season kicks in. The other time is right now.
Merauke-Gove? It's only 1/3 the distance of Bali-Darwin and a much better
wind angle. Probably the easiest sail between the two countries.
But if you're looking to hitch a ride with someone, boats doing that trip would be few and far between