It's the Law: Delaware Boating Regulations

Section 3. Ventilation.

(a) Applicability. This section applies to motorboats, motor vessels, and boats used on the waters of this State and subject to this regulation.

(b) No person shall operate a motorboat or motor vessel, except an open vessel, built after April 25, 1940, and before August 1, 1980, which uses fuel having a flashpoint of 110°F, or less, without every engine and fuel tank compartment being equipped with a natural ventilation system. A natural ventilation system consists of:

1. At least two ventilator ducts, fitted with cowls or their equivalent, for the efficient removal of explosive or flammable gases from the bilges of every engine and fuel tank compartment;
2. At least one exhaust duct installed so as to extend from the open atmosphere to the lower portion of the bilge and at least one intake duct that is installed to extend to a point at least midway to the bilge or at least below the level of the carburetor air intake; and
3. The cowls shall be located and trimmed for maximum effectiveness and in such a manner so as to prevent displaced fumes from being recirculated.

(c) Vessels built after July 31, 1978, shall be exempt from the requirements of subsection (a) of this section for fuel tank compartments that:

1. Contain a permanently installed fuel tank if each electrical component is ignition protected in accordance with 33 CFR § 183.410(a); and
2. Contain fuel tanks that vent to the outside of the motorboat or motor vessel.

(d) Vessels built after July 31, 1980, or which are in compliance with the Coast Guard Ventilation Standard, a manufacturer requirement (33 CFR §§ 183.610 and 183.620), shall be exempt from the requirements of subsections (b) and (d) of this section.

(e) No person shall operate a vessel after July 31, 1980, that has a gasoline engine for electrical generation, mechanical power or propulsion unless it is equipped with an operable ventilation system that meets the requirements of 33 CFR § 183.610(a), (b), (d), (e) and (f) and 183.6209(a).

(f) Vessel owners shall maintain their vessels' ventilation systems in good operating condition (regardless of the vessel's date of manufacture).