The U.S. Supreme Court case Seatrain Shipbuilding Corp. et al. v. Shell Oil Co., et al., 1979, involved a dispute over the interpretation of the Deepwater Port Act of 1974 (DPA). The plaintiffs, Seatrain Shipbuilding and other shipbuilders, argued that Shell Oil's proposed offshore oil terminal violated the DPA because it would not accommodate tankers built in American shipyards to transport Alaskan crude oil to East Coast refineries as required by law under Section 5(a)(1) of DPA which mandates use of US-built vessels for such transportation purposes. Shell countered this argument stating that their project was exempt from these requirements since they were only transporting foreign oil through its port facility and not Alaskan crude oil. The court ruled in favor of Shell Oil Company concluding that Congress did not intend for Section 5(a)(1) to apply when no Alaskan crude is being transported; hence, there was no violation on part of Shell’s proposed deepwater port facility.

In the dissenting opinion for Seatrain Shipbuilding Corp. v. Shell Oil Co., Justice William Rehnquist disagreed with the majority's interpretation of the 1970 amendment to §2 of the Shipping Act, arguing that it was not intended to apply to contracts for ship construction but rather only those related directly to shipping services. He pointed out that Congress had made no explicit mention of ship construction in its discussions about this legislation and argued that if they had intended such a significant change, they would have done so explicitly. Furthermore, he noted that applying this law retroactively could potentially disrupt many existing contracts and create uncertainty within the industry - something which he believed Congress would have wanted to avoid.