All vessels are required to have a Type B, USCG–approved fire extinguisher on board if one or more of the following conditions exist:
- Closed storage compartments in which flammable or combustible materials are stored
- Closed living spaces
- Permanently installed fuel tanks (any tank where the removal of the tank is hampered by the installation of tie-down straps or clamps)
- Flammable or toxic fluids are on board
Approved types of fire extinguishers are identified by the following marking on the label—“Marine Type USCG Approved”—followed by the size and type symbols and the approval number.