Tom Clancy hypothesis on sonar performance...

[Dr.Sid]

These are more likely:

-Chinese destroyer pings
-US subs reflects something, but too little for the destroyer to pick it up
-Chinese sub is closer and gets the echo, but reflects something too
-US gets echo of Chinese sub

or

-Chinese destroyer pings
-US subs reflects something, but too little for the destroyer to pick it up
-Chinese sub is also too far away, somewhere near the destroyer, and it is painted too
-US sub knows everything

or

-Chinese destroyer suspect US sub in specific area, does directional ping
-US subs reflects something, but too little for the destroyer to pick it up
-Chinese sub is a closer, and can detect the echo, while being aside anough not to be painted enough
-US sub knows about destroyer, and can estimate it is at safe distance, but it does not know about the Chinese sub