Mercury 225 Manual page 44

Example of desired air flow through the boat:
POOR VENTILATION
Under certain running and/or wind conditions, permanently
enclosed or canvas enclosed cabins or cockpits with insufficient
ventilation may draw in carbon monoxide. Install one or more
carbon monoxide detectors in your boat.
Although the occurrence is rare, on a very calm day, swimmers
and passengers in an open area of a stationary boat that
contains, or is near, a running engine may be exposed to a
hazardous level of carbon monoxide.
1. Examples of poor ventilation while the boat is stationary:
a
a - Operating the engine when the boat is moored in a
confined space
b - Mooring close to another boat that has its engine
operating
GENERAL INFORMATION
b
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