All state officers, subject to such regulations as the Governor may issue, shall, upon approval of this article, in addition to any deputy authorized pursuant to law to exercise all of the powers and discharge the duties of the office, designate by title emergency interim successors and specify their order of succession. The officer shall review and revise, as necessary, designations made pursuant to this article to insure their current status. The officer will designate a sufficient number of such emergency interim successors so that there will be not less than three nor more than seven such deputies or emergency interim successors or any combination thereof at any time. In the event of an attack, and in the event that any state officer or his deputy, if any, is unavailable following such an attack, the said powers of his office shall be exercised and said duties of his office shall be discharged by his designated emergency interim successors in the order specified. Such emergency interim successors shall exercise said powers and discharge said duties only until such time as the Governor under the Constitution or authority other than this article or other official authorized under the Constitution or this article to exercise the powers and discharge the duties of the office of Governor may, where a vacancy exists, appoint a successor to fill the vacancy or until a successor is otherwise appointed, or elected, and qualified as provided by law; or an officer or his deputy or a preceding named emergency interim successor becomes available to exercise or resume the exercise of the powers and discharge the duties of his office.