Oregon Revised Statutes Small Watercraft § 830.240

(1) Motorboats using fuel having a flashpoint of 110 degrees Fahrenheit or less shall have ventilating systems that meet standards provided by the State Marine Board for the purpose of properly and efficiently ventilating the bilges of every engine and fuel compartment in order to remove any inflammable or explosive gases.

(2) The board may, in accordance with ORS chapter 183, adopt regulations providing standards for ventilating systems. Motorboats so constructed as to have the greater portion of the bilges under the engines and fuel tanks open and exposed to the natural atmosphere at all times are not required to be fitted with ventilators.