46 CFR §169.567

1. (a)The minimum number of portable fire extinguishers required on each vessel is determined by the Officer in Charge, Marine Inspection, in accordance with table 1 to § 169.567(a) and other provisions of this subpart.
2. (b)Table 1 to § 169.567(a) indicates the minimum required classification for each space listed. Extinguishers with larger numerical ratings or multiple letter designations may be used if the extinguishers meet the requirements of the table.
3. (c)All portable fire extinguishers installed on vessels must be of an approved type.
4. (d)Portable fire extinguishers must be stowed in a location convenient to the space protected.
5. (e)Portable fire extinguishers must be installed and located to the satisfaction of the Officer in Charge, Marine Inspection.
6. (f)Portable fire extinguishers which are required to be protected from freezing must not be located where freezing temperatures may be expected.