The Navy on Saturday christened the first ship of its newest class of destroyers, a $3 billion, 610-foot-long warship named after the late Admiral Elmo Zumwalt. ‘‘This ship is a modern marvel, and it’s going to take smart and creative and hard-working sailors like Bud Zumwalt to operate it,’’ Secretary of the Navy Ray Mabus told the crowd of thousands at Bath Iron Works, where the ship has been under construction since 2009. The Zumwalt was supposed to be christened in October, but the ceremony was rescheduled because of the federal government shutdown. The ship is to be delivered to the Navy late this year and to enter service in 2016. (AP)