Motorboats are required to carry readily accessible fire extinguishers accepted for marine use by the Coast Guard. The size and number of extinguishers accepted for use on motorboats depends on the size of the boat and whether or not there is a fixed extinguishing system installed aboard. Fire extinguishers are not required for outboard pleasure boats less than 26 feet in length, not carrying passengers for hire, without permanently installed fuel tanks and which do not have spaces in which explosive or flammable gases or vapors can collect.
Extinguishers are classified by letters and numbers according to the type and size of fire they can put out. The letter indicates the type of fire the unit is designed to extinguish: Type "A" is for combustible solids like wood, "B" is designed to extinguish flammable liquids such as gasoline, oil and grease fires, "C" is for electrical fires and Type "D" is for combustible metals like magnesium. The number indicates the relative size of the extinguisher (minimum extinguishing agent weight).
Fires involving burning wood and paper (Class A) can be put out with water, but never use water on gasoline, oil or electrical fires. Water will cause a gasoline or oil fire to spread and in the case of an electrical fire, further damage electrical equipment. Most boat fires consist of burning flammable liquids such as oil or gasoline (Class B).
Some boat fires are caused by faulty electrical wiring (Class C). The current overloads the wire, gets it hot and sets the insulation on fire. An extinguisher must be able to put out this fire without giving the user a shock. Use dry chemical, CO2, or Halon/Freon.
Type of extinguisher Class of fire Carbon Dioxide (CO2) A B C Halon/Freon A B C Dry Chemical B C Foam B Water A
Coast Guard approved extinguishers are hand-portable, either B-I or B-II classification and have a specific marine type mounting bracket. It is recommended that the extinguisher be mounted in a readily accessible position. Never try an extinguisher to see if it works properly.
Inspect fire extinguishers monthly to make sure that:
- Seals and tamper indicators are not broken or missing.
- Pressure gauges or indicators read in the operable range. (Note: CO2 extinguishers do not have gauges.)
- There is not obvious physical damage, corrosion, leakage or clogged nozzles.
Minimum number of hand-portable fire extinguishers required are as follows:
Length of Vessel No Fixed System Approved Fixed System Less than 26' 1 B-I None 26' to less than 40' 2 B-I or 1 B-II 1 B-1 40' to 65' 3 B-I or 1 B-II and 1 B-I 2 B-I or 1 B-II