Almost two years ago, I posted the answers to a private trivia challenge I was involved in. In the interim, the US Navy has intentionally sunk the ex-USS AMERICA (Hull #66). That ship was subject to a series of real-world tests you rarely get to do -- survivability of a modern aircraft carrier when hit with modern weapons. The details and results are classified, but in the end the ex-AMERICA slipped quietly beneath the surface having survived the weapons, but not the scuttling charges.
Another carrier will sink in the coming months was sunk when the ex-USS ORISKANY (Hull #34) will be was sunk off the coast of Pensacola, FL. Delayed by the EPA, the sinking will happen some time around occurred May 17, 2006. The ex-ORISKANY will be is the largest ship intentionally sunk to become a reef.
That earlier post has all the links to the stories.