All i can say is the last patrol of my U-196 game (see log, patrol 4) was all along the easteran aussy coast. Just hug the shallow water line, along the deep water side of it. I encountered 3 convoys, and a few juicy small convoy's.
I returned to port with 6 torpedo's. SO i could have sank a bit more then i did.
Overall, i think the players of GWX would be remiss if they didnt spend some time in the indian ocean. The place is alot more populated. Just dont expect any renown for any psudeo patrol grids assigned. Infact i ignored those completly. Eastern affrica? Suuure.. i went to oz instead