39 U.S.C. § 5605Section
§ 5605. Contracts for transportation of mail by vessel
The Postal Service may contract for the transportation of mail by vessel without advertising for bids.
(Pub. L. 91–375, Aug. 12, 1970, 84 Stat. 773; Pub. L. 109–435, title X, §1002(b)(3), Dec. 20, 2006, 120 Stat. 3255.)