My experience - 5 trips - is that it's very hard to go west to east across the bottom. I have done it once and since always prefer to go clockwise around Australia
. The prevailing easterlies along the south coast make it almost impossible except in a hard beat to windward. Some head
for Tasmania, but that's still a beat. You have two swell patterns to contend with - the big SW swells and then whatever easterly swell is churned up by the wind
It is of course shorter across the bight, and it is possibly viable at the change over of the seasons (if you are lucky), as the high pressure cells move down out of the continent at the end of winter; alternatively as the highs move up on to the continent at the end of summer. You have to watch the weather
patterns, but this can be October, or end of March / April. I have just done the trip, east to west, last March, and had easterlies all the way - and a very lumpy sea. My previous trip was 5 years ago, early-mid April, and I had light westerlies. Had to motor
much of the way, but it would have been viable to go west to east at that time. I know of several boats that crossed from West to East last Sept / Oct. You have to watch the weather
patterns - you want a high centered up along the coast so light westerlies. You have to be prepared to motor
and prepared to weather one or two cold fronts.