> how many bars of pressure can the black box take, because were that's situated on
> the aircraft surely has taken it down to the bottom of the atlantic withit, IF being the
> case. That blackbox will crush.
The US specifications, which I think are similar to those in other countries, require that they withstand depths of up to 20,000 feet.
http://www.ntsb.gov/aviation/CVR_FDR.htm
Note also that the NTSB site suggests that the pinger can be received at up to 14,000 feet (2.65 statute miles), though the way the description is written, one could infer that it won't work below 14,000 feet. In any event, a surface ship wouldn't pick up the signal if the box was at a depth of more than 14,000 feet without some sort of towed antenna.