In our experience, the EAC is a fickle beast, and one needs to modify ones strategy to meet current
(ho,ho) conditions. For example, one year trying to round Cape Byron we encountered FIVE knots of south-flowing current
. Got a real good look at the lighthouse and the tourists (we were that close inshore). The next year, at about the same season, we had about a half knot
of north-flowing current in the same place. Go figger!
So, our practice is to sail the rhumb line and if it is buggered with adverse current, then start experimenting with evasive manuevers.