If you're talking about the type that use fans that start before the motor will start, it's to dispell any gas or petrol fumes that might accumulate in the bilge before any sparks are generated by the starter motor or ignition
Turn on the ventilation system before you start the engine; normally on inboard engines which are in a confined space.
Its purpose is very important. It takes care of any residual gas vapors and exhaust them out, so that when you start your boat, you don't blow your own booty out of the water.
To allow the engine to breathe, and help to vent fumes as well.
Mechanical Ventilation System
Mechanical
must have a mechanical ventilation system (EQ-17)
Mechanical unless your boat was built before July 31, 1980.
Mechanical
The purpose of a ventilation system is to ensure good airflow into the area where one works or lives. A ventilation system helps air circulate better allowing fresh air to be pumped in.
Inboard gasoline boats built after July 31st, 1980 must have what type of ventilation system?
Inboard gasoline boats built after July 1981 are required to have a ventilation system that meets the standards set by the U.S. Coast Guard. This typically includes both natural and powered ventilation to ensure that any potentially explosive gasoline vapors are effectively dissipated. The system must be designed to allow for proper air circulation in the engine compartment, reducing the risk of fire or explosion. Compliance with these regulations is crucial for the safety of the vessel and its occupants.
Inboard gasoline boats built after July 31, 1980, must have a ventilation system that includes at least two ventilation ducts to the engine compartment, ensuring proper air circulation. These systems typically feature both intake and exhaust vents to help dissipate flammable vapors. Additionally, the system should be designed to operate effectively even when the boat is underway, enhancing safety by reducing the risk of explosion.