As
mm43 has pointed out many times, the surface currents of the equatorial Atlantic in the region where AF447 went down are highly variable and difficult to predict. Test buoys dropped and followed a year later were not helpful; BEA's very smart Drift Group pointed to areas that yielded no joy during the Phase 3 ROV/AUV effort.
If you approach the impact location problem from another angle, simply using the reported LKP at 02:10 and the cotemporaneous ACARS cascade, you are correctly applying Occam's Razor. The aircraft was in normal cruise until the LKP (see my June
Post #1178 and diagram). If upset was at 02:10 (or a little before), the aircraft simply could not have traveled anywhere near to the edge of a 40nm radius of interest (see
Post #1349) in 4 minutes of rapidly descending and assumedly uncontrolled flight. You would conclude that the hull will be found close-in to the LKP.
The areas immediately beneath the LKP and southeastward a few km towards the slick have not yet been searched.
I do hope they start there.
GB