Excellent article about the search area:
http://www.foreignpolicy.com/articles/2014/03/26/mh370_and_the_secrets_of_the_deep_dark_indian_ocean
Storms are the rule rather than the exception in this part of the world, plagued by the Roaring Forties -- the never-ending winds that howl around 40 degrees latitude south. The weather, combined with the fact that this zone, just north of Antarctica, is the only place where water can flow around the globe without hitting land, means that the waves are among the highest in the world. (Surfing is inadvisable.) That these are some of the deepest parts of the Indian Ocean, with a rugged and volcanic ocean floor, decreases the likelihood that the black boxes would be retrievable. All of which adds up to an almost impossible race against time: Those black boxes have limited battery life and will likely stop transmitting around April 7.