Chapter 18: Bilge Systems, Fire Mains, and Fire Extinguishers
Fire Extinguishers
Coast Guard–approved fire extinguishers are required on all boats where a fire hazard can be
expected from engines or any fuel. Extinguishers are classified by a letter and a number symbol.
The letter indicates the type of fire the unit is designed to extinguish. Type B, for example, is de-
signed to extinguish flammable liquids such as gasoline, oil, and grease fires. The number indicates
the relative size of the extinguisher. The higher the number, the larger the extinguisher.
The required extinguishers are either B-I or B-II classification and have specific marine
mounting brackets. They should be installed where they are easily accessible in compartments
with a possible fire source or just outside such a compartment.
Classes of Fires and Fire Extinguishers
A.(Ash producing) wood, paper, natural fabric, etc.
B.(Boiling/liquid) diesel, gasoline, grease, kerosene, naphtha, paint, etc.
C.(Current/electric) any electrical fire
D.(Deadly) volatile and/or poisonous chemicals, flares, explosives, magnesium, etc.
K.(Kitchen) vegetable oils, animal oils, or fats in cooking appliances. This is primarily for
commercial kitchensExtinguisher markings can be confusing because extinguishers can be approved for several
different types of hazards. For instance, an extinguisher marked “Type A, Size II, Type B:C, Size
I” is a B-I extinguisher (in addition to being an A and C type). Look for the part of the label that
says “Marine Type USCG,” and check to see that Type B is indicated. Portable extinguishers
of either size I or II are suitable. Size III or larger are too cumbersome for use on most boats.
All marine fire extinguishers should be B-type (with any other type listed in addition being
just fine).
TABLE 18-4. FIRE-EXTINGUISHER CLASSES AND SIZES
Foam C0 2 Dry Chemical Halon* Halocarbon†Classes gal. (L) lb. (kg) lb. (kg) lb. (kg) lb. (kg)
B-I (Type B, Size I) 1.25 (4.7) 5 (2.3) 2 (0.9) 2.5 (1.1) 5 (2.3)
B-I (Type B, Size II) 2.5 (9.5) 15 (6.8) 10 (4.5) 10 (4.5) 15 (6.8)
*Many tables still reference Halon. Halon has been banned to protect the ozone layer.
FE 241, FM 200, FE-227, or HFC-227 are the common replacements.
†Halocarbon is either hydrochlorofluorocarbons (HCFCs) or hyrdrofluorocarbons (HFCs).
TABLE 18-5. MINIMUM NUMBER OF REQUIRED HANDHELD EXTINGUISHERS—
BOATS UP TO 65 FT. (19.8 M)
With ApprovedVessel Length With No Fixed System Fixed System
Open boats under 16 ft. (4.9 m) (1) B-1 None
Open boats over 16 ft. (4.9 m) (2) B-2 None
All boats less than 26 ft. (7.9 m) (2) B-I None
26 ft. to less than 40 ft. (7.9 to 12.2 m) (3) B-I (2) B-I
40 ft. to 65 ft. (12.2 to 19.8 m) (4) B-I (3) B-I or (2) B-II
(Continued)