It does and it will.
How hard? I do not know.
It would certainly depend on the depth underneath the wreckage site.
Crash survivable boxes are not flotation devices. They will be with the wreckage.
I heard (and of course, I know zero on this subject) that the depth where the wreckage has been found was something like 3 miles and the boxes emit thru water up to about a mile (not sure where I heard this, maybe I made it up!) If so, it may not be much help. But, I hope that’s wrong.