Section 157.300 - Qualifications for exemptions under this part(a) Each vessel under § 157.10a or § 157.10c of this part may qualify for an exemption from the requirements of § 157.10a or § 157.10c of this part if- (1) The vessel loads and discharges cargo only at ports or places within the United States, its territories, or its possessions; and(2) The application for exemption meets § 157.302 .(b) Except where the owner can show good cause, a vessel is not granted an exemption under this subpart if a previous exemption for the vessel has been revoked by the Coast Guard under § 157.308(a)(1) or § 157.308 (a)(2) .CGD 79-126, 46 FR 3513, Jan. 15, 1981, as amended by CGD 82-28, 50 FR 11630, Mar. 22, 1985