So over hundreds of miles it seems like the flow is laminar. Australia is huge - the little circles there would suggest that mostly the flow is laminar in most areas. Or am I misunderstanding your pointWater flow at the great barrier reef. 9 months south, 3 months north. http://www.mrstevennewman.com/geo/GBR/Hydrological.htm
Source: http://www.marine.csiro.au/LeafletsFolder/37eac/