In the 1943 case of Mahnich v. Southern Steamship Co., the U.S. Supreme Court ruled in favor of a seaman who was injured on board due to negligence by his employer, despite having been warned about potential danger prior to his injury. The court held that under maritime law, an employer's duty to provide a safe working environment for its employees is absolute and cannot be diminished or excused because an employee may have acted negligently himself. This ruling reinforced the principle that ship owners owe their crew members a strict duty of care and are liable for injuries resulting from any breach of this obligation, regardless if workers were aware of potential risks associated with their tasks.

In the dissenting opinion for Mahnich v. Southern Steamship Co., Justice Frankfurter argued that the majority's decision to hold a shipowner liable for injuries sustained by an employee due to unsafe conditions, even when those conditions were known and accepted by the worker, was inconsistent with established maritime law principles. He contended that this ruling disregarded precedent which had previously held that seamen who knowingly accept dangerous working conditions cannot later sue their employers for resulting injuries. Furthermore, he believed it was not within the Court's jurisdiction to change these rules of liability without legislative action from Congress. In his view, such changes should be made through legislation rather than judicial interpretation in order to maintain consistency and stability in maritime law.