The U.S. Supreme Court case Sun Ship, Inc. v. Pennsylvania et al., 1979, dealt with the issue of whether federal law preempts state workers' compensation laws in cases involving maritime injuries. The court held that both federal and state remedies were concurrently available to maritime workers injured on the job within a state's territorial waters under certain circumstances, even though their work was considered "maritime but local." This decision was based on an interpretation of the Longshoremen's and Harbor Workers' Compensation Act (LHWCA), which provides for federal benefits to such employees; however, it does not expressly exclude them from also seeking relief under applicable state laws. Therefore, states could provide additional or supplementary benefits without conflicting with or being preempted by federal law.

In the dissenting opinion for SUN SHIP, INC. v. PENNSYLVANIA et al., Justice Rehnquist disagreed with the majority's interpretation of congressional intent regarding concurrent jurisdiction under both state workers' compensation laws and the Longshoremen's and Harbor Workers' Compensation Act (LHWCA). He argued that Congress intended to establish a comprehensive federal scheme for maritime injuries, which would preclude overlapping state remedies. The majority’s decision allowing dual coverage could lead to inconsistent results depending on where an injury occurred or whether a particular employer had secured insurance under one statute but not another. Furthermore, he contended that this ruling might encourage forum shopping by claimants seeking more favorable benefits or procedural rules in different jurisdictions. In his view, such potential inconsistencies undermined uniformity in maritime law and contradicted Congress’ intention when enacting LHWCA.