Earlier this week the US Navy scuttled the decommissioned aircraft carrier USS Oriskany as the start of a program to dispose of old ships and create artificial reefs in the process. The site is expected to be very popular with recreational divers, although it's far enough down that the flight deck, at between 135 and 140 feet, will be accessible to advanced divers only.
One of the ship's claims to fame is as the carrier from which John McCain flew on his last, ill-fated mission over North Vietnam.
Here is a Yahoo! slideshow of the sinking; more photos here.