"Vaughn" wrote in message
...
On 3/26/2014 4:37 AM, Keith Willshaw wrote:
1) The Indian Ocean is BIG
2) Nuclear Submarines typically operate submerged with no radar
working
3) DE Submarines tend to lurk around main shipping routes and also
practise EMCON

Correct me if I'm wrong, but:

Listening for a "ping" is a passive operation. Simply listening
involves no emissions of any kind from the submarine. Still, given
the published 2 KM range of the black box's pinger, the chances of a
submarine blundering close enough to detect it are small given the
vast search area.

I haven't seen whether that refers to the straight-line spherical
radius to the box or the circular radius around it on the surface. A
sub could more easily listen below the Deep Scattering Layer. However
having more than one nation's boats searching, and recording each
others' sound signatures, may not be a good idea for us.