President said:how the submarine fight with aircraft carrier? any tactics?
Unless the carrier group is located and that location is somehow conveyed to the subs without being intercepted and without subs location itself being compromised, then the subs have a chance. Of course, the datalink to the subs must be kept, since the carrier group is not likely to be staying at one place for hours at a time, just waiting for (relatively) slow subs to reach them.
IF all that location and targeting stuff can be done without revealing subs location, a battery run attack force of some dozen or more subs can, in my opinion, seriously endanger a lone carrier group. More likely than not no sub would survive such an attack and get to go home but at the same time, such a 'brave' suicide attack could result in some hits, perhaps even a sinking of some elements of the carrier group. (anyone know how many torpedo hits would be needed to sink a nimitz class carrier?)