Which statement is true concerning the "Discharge of Oil Prohibited" placard?

The "Discharge of Oil Prohibited" placard is specifically mandated by regulations for certain vessels, particularly those that are 26 feet or greater in length. This requirement serves as a critical reminder to vessel operators about the legal prohibitions against the discharge of oil into U.S. waters, emphasizing environmental protection and adherence to federal laws.

While the other statements may contain elements of truth or may apply under different circumstances, the primary focus of this regulation pertains to the size of the vessel. Thus, any vessel meeting the size criteria must have this placard displayed prominently to ensure compliance. This reinforces the importance of awareness regarding oil spills and environmental responsibility amongst operators of larger vessels.