Sunday, April 11, 2021

Fire Extinguishers on Your Boat

Photos by Keith Wohltman | Three Marine-type fire extinguishers, classified as 5, 10 (B:C type) and 110 (A:B:C). All are considered B-I, and should be mounted to comply with Coast Guard approval.

Photos by Keith Wohltman | Three Marine-type fire extinguishers, classified as 5, 10 (B:C type) and 110 (A:B:C). All are considered B-I, and should be mounted to comply with Coast Guard approval.


By Keith Wohltman 

The US Coast Guard has regulations for the minimum number of extinguishers the average boat needs to have onboard. The American Boat and Yacht Council (ABYC) and the National Fire Protection Association (NFPA) recommend you carry an additional extinguisher above the minimum.

US Coast Guard-approved, marine-type fire extinguishers are required on boats where a fire hazard could be expected from the engines or fuel system. Extinguishers are classified by a letter and number symbol. The letter indicates the type of fire the unit is designed to extinguish. The number indicates the amount of the extinguishing agent contained in the extinguisher; the higher the number, the greater the amount of agent in the extinguisher.

US Coast Guard-approved extinguishers required for boats and PWCs are hand-portable, and have either B-I or B-II classification, and must be provided with a mounting bracket. While not required, it is recommended that the extinguishers be mounted in a readily accessible location. Hand-portable extinguishers will be either a Size I or II. Size III and larger are too big for use on most recreational boats.

How do you know if your boat requires a fire extinguisher? Fire extinguishers are required on boats when any of the following conditions exist:

  • There are closed compartments and compartments under seats where portable fuel tanks may be stored.
  • There are double bottoms not sealed to the hull or that are not completely filled with flotation materials.
  • There are closed living spaces.
  • There are closed stowage compartments, in which combustible or flammable materials are stored.
  • There are permanently installed fuel tanks (Fuel tanks secured so they cannot be moved in case of a fire or other emergency are considered permanently installed. Also, if the weight of a fuel tank is such that persons on board cannot move it, the US Coast Guard may consider it permanently installed).

Fire extinguishers for your boat must be Marine-rated and US Coast Guard approved. Extinguisher classifications are based on the types of fires they are designed to fight. On a boat you will likely encounter three types of fires.

A – Ordinary Combustibles: Fires in paper, cloth, wood, rubber, and many plastics.

B – Fires in oils, gasoline, some paints, lacquers, grease, solvents, and other flammable liquids.

C – Fires in wiring fuse boxes or energized electrical equipment, computers, and other electrical sources.

There is also an extinguisher classification of “A, B and C.” It is a DRY CHEMICAL agent and suitable for multiple types of fires. An extinguisher marked “Type A, Size II; Type B; C, Size I” is acceptable as a Type B-I extinguisher. Also, if a US Coast Guard-approved fixed fire extinguishing system is installed for the protection of the engine compartment, the required number of extinguishers may be reduced in accordance with the chart shown.

Unfortunately, when you go to a marine supply store to purchase an extinguisher you probably will



not see “B-I” or “B-II” labeled on the extinguisher box. The Coast Guard uses a classification related to weight of fire fighting agent. The packaging, however, will use the Underwriter Laboratories (UL) classification, such as “5 B:C” or “10 B:C” (both are considered type USCG “B-I”). The UL classification represents the square footage of fire the extinguisher is designed to combat. That means a “5 B:C” will fight a five square foot fire. This can be very confusing. A type “B-II” extinguisher requires ten pounds of dry chemical agent, but the “10 B:C” unit only has two and a half pounds of agent. It should not be misinterpreted as a “B-II” extinguisher. If you are unsure which extinguisher you need, don’t hesitate to ask the salesman.

Remember to check your fire extinguishers monthly and replace immediately if necessary. What to look for:

  • Seals and tamper indicators are not broken or missing.
  • Pressure gauges or indicators read in the operable range.
  • There is no physical damage, corrosion, leakage, or clogged nozzles.

Southwest Florida’s weather can play havoc with items stored on a boat and fire extinguishers are not immune to this situation. Flotilla 95 recommends replacing fire extinguishers every 3-4 yrs. The year of manufacture is stamped on the bottom of the extinguisher.

Please be aware that there was a fire extinguisher recall by the manufacturer, Kidde. The items affected are Kidde brand, black plastic Zytel® nylon valve disposable extinguishers, both ABC and BC rated models manufactured between July 23, 2013 and October 15, 2014 and sold between August 2013 and November 2014. The affected fire extinguishers are white or red in color and are either ABC or BC-rated. The Kidde logo and serial number are located on the nameplate. The date code is an ink jet 10-digit number stamped on the side of the cylinder near the bottom. Digits 5-9 of this number convey the day and year of manufacture. Affected units will have the following five digits in a date code:

2013: XXXX20413X through XXXX36513X

2014: XXXX00114X through XXXX28814X 

Contact Kidde by phone 855-283-7991 (8 AM to 5 PM weekdays) or go to which links you to: to determine if you have a recalled extinguisher in service. Contact Kidde to obtain a replacement.

For more information about safe boating courses, contact Joe Riccio at 239-384-7416 or To schedule your free Vessel Safety Check, please call John Moyer at 239-248-7078 or the Coast Guard Auxiliary Station – Flotilla 95 at 239-394-5911, or email John at If you are interested in joining Flotilla 95, USCG Auxiliary, please call Bob Shmihluk at 215–694-3305. 

Keith Wohltman retired to Marco Island from New Jersey, where he spent decades on the water. He joined the U.S. Coast Guard Auxiliary to help make boating safer around Marco and the 10,000 Islands. He has served as the Flotilla Commander and a Coxswain and is currently the Public Affairs Staff Officer for Marco Island’s Flotilla 95.

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