SAN DIEGO, Dec. 14, 2015 /PRNewswire/ — On Saturday, December 12, General Dynamics NASSCO launched the first ship in a series of ECO Class tankers for the SEA-Vista fleet. The christening and launch ceremony took place at the company’s shipyard in San Diego. The ship, the Independence, is a 610-foot, 50,000 deadweight-ton, and LNG-conversion-ready product tanker…