(a) In General.—The principal of an obligation may not be guaranteed in an amount greater than the amount determined by multiplying the percentage applicable under subsection (b) by—

(1) the amount paid by or for the account of the obligor (as determined by the Secretary or Administrator, which determination shall be conclusive) for the construction, reconstruction, or reconditioning of the vessel used as security for the guarantee; or

(2) if the obligor creates an escrow fund under section 53715 of this title, the actual cost of the vessel.

(b) Limitations on Amount Borrowed.—

(1) In general.—Except as otherwise provided, the principal amount of an obligation guaranteed under this chapter may not exceed 75 percent of the actual cost or depreciated actual cost, as determined by the Secretary or Administrator, of the vessel used as security for the guarantee.

(2) Certain approved vessels.—The principal amount may not exceed 87.5 percent of the actual cost or depreciated actual cost if—

(A) the size and speed of the vessel are approved by the Secretary or Administrator;

(B) the vessel is or would have been eligible for mortgage aid for construction under section 509 of the Merchant Marine Act, 1936, or would have been eligible except that the vessel was built with a construction-differential subsidy and the subsidy has been repaid; and

(C) the vessel is of a type described in that section for which the minimum down payment required by that section is 12.5 percent of the cost of the vessel.

(3) Fishing vessels and fishery facilities.—For a fishing vessel or fishery facility, the principal amount may not exceed 80 percent of the actual cost or depreciated actual cost. However, debt for the vessel or facility may not be placed through the Federal Financing Bank.

(4) OTEC.—For an ocean thermal energy conversion facility or plantship constructed without a construction-differential subsidy, the principal amount may not exceed 87.5 percent of the actual cost or depreciated actual cost of the facility or plantship.

(c) Security Involving Multiple Vessels.—The principal amount of an obligation having more than one vessel as security for the guarantee may not exceed the sum of the principal amounts allowable for all the vessels.

(d) Prohibition on Uniform Percentage Limitations.—The Secretary or Administrator may not establish a percentage under any provision of subsection (b) that is to be applied uniformly to all guarantees or commitments to guarantee made under that provision.

(e) Prohibition on Minimum Principal Amount.—The Secretary may not establish, as a condition of eligibility for a guarantee under this chapter, a minimum principal amount for an obligation covering the reconstruction or reconditioning of a fishing vessel or fishery facility. For purposes of this chapter, the reconstruction or reconditioning of a fishing vessel or fishery facility does not include the routine minor repair or maintenance of the vessel or facility.