Vinnie Boombatz
Today's sonobuoy search area is at/near where the Hai Xun 01 heard the pings on 05 April, and it's basically on the #7 arc.
The aerial search areas are on/near the Inmarsat 400 kt path (red) and one of the NTSB suggested paths. Overlay comparing the search areas:
http://i.imgur.com/peWnXpJ.png