Washington law requires tug escorts for tankers in restricted waters

Covered oil tankers must travel with one or more escort tugs that meet a minimum combined engine power. This covers tankers rated at 40,000 to 125,000 deadweight tons in Washington waters east of the Discovery Island–New Dungeness light line and throughout the Puget Sound area, including the San Juan Islands. Deadweight tons measure carrying capacity. The tugs’ combined shaft horsepower must be at least 3,000 or five percent of the tanker’s deadweight tons, whichever is greater. Tankers traveling empty or carrying ballast instead of cargo do not need an escort. The law took effect June 11, 2026.

Tankers above 125,000 deadweight tons cannot cross the stated boundary without U.S. Coast Guard authorization. The restriction applies east of the line running south from Discovery Island light to New Dungeness light. The U.S. Coast Guard may authorize passage under the federal rule named in the law.

Covered smaller tankers and towed oil vessels must use tug escorts in Rosario Strait and connected waterways to the east. This covers oil tankers between 5,000 and 40,000 deadweight tons and towed vessels or barges above 5,000 deadweight tons designed to carry bulk oil inside their hulls. It includes tank barges mechanically joined to tugs. Escort tugs must have at least 2,000 combined shaft horsepower, equal to five percent of a 40,000-deadweight-ton tanker’s capacity. The rule excludes vessels providing refueling services, general cargo deck barges, and vessels traveling empty or carrying ballast instead of cargo. The Board of Pilotage Commissioners may adjust or suspend this escort rule through its rulemaking process. This smaller-vessel escort requirement has a September 1, 2020, start date.