Essential requirement:
The engine compartment shall be ventilated. The dangerous ingress of water into the engine compartment through all inlets must be prevented.

Harmonized standard:
• EN ISO 11105:1997 Small craft - Ventilation of petrol engine and/or petrol tank compartments

Diesel engine compartments shall be ventilated according to the recommendations of the engine manufacturer.

Compartments containing petrol engines or petrol tanks shall be sealed from enclosed accommodation spaces. Unless open to the atmosphere, each compartment shall have natural or powered ventilation:

Natural ventilation	Powered ventilation

Petrol engine crafts shall show the following label at the steering console:

For the ingress of water into the engine compartment requirements see the minimum down flooding heights as given in ISO 12217.