Specifically, the Office of Marine Safety adopted regulations requiring tank vessel operators to submit an oil spill prevention plan for state review and approval.

The court unanimously held that Congress intended the United States Coast Guard to be the sole national authority regarding the design, construction, maintenance and certain operational requirements of tank vessels.

[2] This unanimous decision upheld and expanded previous case law, including Gibbons v. Ogden and Ray v. Atlantic Richfield regarding the federal government's strong role and preemptive powers in regulating interstate commerce.

"[5] The Court held that "Washington's regulations regarding general navigation watch procedures, crew English language skills and training, and maritime casualty reporting are pre-empted by the comprehensive federal regulatory scheme governing oil tankers; the case is remanded so the validity of other Washington regulations may be assessed in light of the considerable federal interest at stake.

"[6] The state of Washington did not pursue the remand back to the 9th Circuit Court of Appeals, but withdrew all of its regulations related to tank vessel oil spill prevention plans.