Nathan Owen Rosenberg has been named to the new position of chairman of Submersible Systems, a Huntington Beach-based manufacturer of Spare Air, an emergency air supply for divers and for the military. Rosenberg's primary focus will be developing business and sales strategies, as well as coordinating marketing programs. A year ago, Rosenberg's marketing consulting firm, Rosenberg Solomon, became controlling partner of Submersible. During his previous military and government career, Rosenberg was executive support officer to the secretary and deputy secretary of defense. He later became national defense adviser to Senate Majority Leader Robert Byrd, D-W.Va.