General Dynamics-NASSCO on Saturday christened the 784-foot USNS Hector A. Cafferata Jr., the last of six super-sized sea-based platforms the company has built for the Navy. The Expeditionary Sea Bases (ESBs) are designed for mine countermeasures, special operations, and humanitarian relief. They also can be used to deploy forces and can handle helicopters and MV-22 tilt-rotor aircraft, which are mostly used to transport Marines. The Navy someti…