In response to posts regarding the difficulties posed in recovery operations in the particular search area I would add as follows.
I understand the search area is over the Wharton Basin. A deep drilling operation of the sea bed of this basin has been carried out some years ago for scientific purposes. I would imagine the search effort being conducted employ the benefit of the knowledge gained from this survey. Detailed information on the deep drilling survey, bottom depths and deposits may be found at the following links.
http://www.deepseadrilling.org/26/volume/dsdp26_09.pdf
http://www.deepseadrilling.org/22/vo..._appendixI.pdf
http://www.deepseadrilling.org/26/volume/dsdp26_36.pdf