Section 142.231 - Exception for portable and semi-portable fire extinguishers required for existing towing vessels(a) Previously installed fire extinguishers with extinguishing capacities smaller than what is required by § 142.230 of this part need not be replaced and may be continued in service so long as they are maintained in good condition to the satisfaction of the OCMI.(b) All new equipment and installations must meet the applicable requirements in this part for new vessels.USCG-2017-1060, 83 FR 8181 , Feb. 26, 2018