The Secretary of Transportation oversees eleven agencies, including the Federal Aviation Administration, the Federal Highway Administration, and the National Highway Safety Administration. They want to "develop and coordinate policies that will provide an efficient and economical national transportation system, with due regard for need, the environment, and the national defense."
The Secretary of the Navy is the Chief Executive Officer of the Department of the Navy, a military department within the department of Defense. This was a cabinet position until 1949, when they were made subordinate to the Secretary of Defense. All authority within the Navy and Marine Corps, unless exempted by law, is derivative of the authority of the Secretary of the Navy. They are responsible for recruiting, organizing, supplying, equipping, training, mobilizing, and demobilizing. They are responsible for overseeing construction and repair of Navy vessels and equipment. They are supposed to administer the military justice system. They are supposed to implement policies and objectives established by the Secretary of Defense.