A series of joint naval drills between the United States and France recently didn't quite turn out the way the US, no doubt, expected. The practice scenario ended with the French nuclear submarine that was acting the part of an enemy ship "sinking" the American aircraft carrier and most of its escort.
The exercises took place over 10 days starting in mid-February off the coast of Florida. The French nuclear attack submarine (SNA) — named Saphir — joined US Carrier Strike Group 12, comprising the aircraft carrier USS Theodore Roosevelt (nicknamed the "Big Stick"), several Ticonderoga cruisers or Arleigh Burke destroyers and a Los Angeles class nuclear attack submarine.
http://sputniknews.com/news/20150306...#ixzz3TuTKFKHZ

I've to wonder about this. Years ago a Chinese sub allegedly surfaced in the midst of a cbg, you may remember that one. In my mind it would be better to say you didn't see/hear an enemy sub sneaking in, even allowing one to surface nearby, and keep quiet about your capabilities. Then again, maybe the Chinese and French subs did get past all our expensive toys.