CNN The Situation Room December 31, 2014 22:12:00
Mountain floor that has deep crevasses that causes the force in the ocean to push debris. that debris is not going to move much at all. in fact it probably won't so they have to find that. also consider the channel shallow. this is good news for the pinger locators. it doesn't have to work and bounce off different frequencies or different walls and crevasses as mentioned and they should get a handle on it. quickly for you, this is the picture out of the c130 aircraft that shows you the rainfall and how saturated it is and this is playing a role in the low visibility and at least the dive crews...
Source: archive.org