The Secretary shall designate a vessel as an American Great Lakes vessel if—

(a) The vessel is documented under the laws of the United States;

(b)

(1) The vessel is not more than 6 years old, and not less than 1 year old, on the effective date of the designation; or

(2) The vessel is not more than 11 years old, and not less than 1 year old, on the effective date of the designation, and the Secretary determines that suitable vessels are not available for providing the type of service for which the vessel will be used after designation;

(c) The vessel has not been previously designated as an American Great Lakes vessel; and

(d) The person who will be the owner of the vessel at the time of such designation agrees to enter into an agreement with the Secretary which provides that if the Secretary determines that the vessel is necessary to the defense of the United States, the United States Government shall have, during the 120-day period following the date of any revocation of such designation an exclusive right to purchase the vessel for a price equal to—

(1) The approximate world market value of the vessel; or

(2) The cost of the vessel to the owner less an amount representing reasonable depreciation of the vessel, whichever is greater.