a wave passing through a body of water isn't actually moving water-- it's a 'wave' of energy making water particles move vertically, but not really far in a lateral direction-- that would be the currents that do that.
and the major currents in the India Ocean-- it's funny, I've been researching this for a novel- run south, down the east coast of Africa, and then circulate eastwards, across the southern half of the ocean-- so any rubbish suspended in the upper layer of water off the east coast of Africa would eventually hit the west coast of Australia.
anything floating on the surface would be pushed westwards by the wind, until it got to 10 degrees north or south of the equator, where the trade winds would push it east again
sorry z, but geography and physics don't back this up...
and in most other terms, Aceh is still more screwed than Somalia by this disaster