Which fire extinguishers would be best suited for use on board a boat?

Answer 1

Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. Nearly all powerboats are required to have at least one portable Class B fire extinguisher (i.e., USCG approved B-I or B-II).

Other types of extinguishers are optional, depending upon what types of fuels may catch fire, such as Class A for "ordinary combustibles" and Class C for energized electrical fires. Class ABC extinguishers are quite popular.

The numerical rating BEFORE the letter B, for class B extinguishers, indicates the approximate number of square feet of fire it can extinguish (i.e., with no significant depth).

The numerical rating (I, II, III) AFTER the letter B indicates Coast Guard classification. For example, a UL 5-B:C, rated for 5 sq ft of liquid fire, would be a USCG B-I extinguisher (with 2 pounds of dry chemical).

To obtain a USCG B-II rating you would need the equivalent of 10 pounds of dry chemical, such as having two UL 3-A, 40-B:C extinguishers, or a 15-pound CO2 extinguisher, or 2 1/2 gallons of AFFF "foam" (UL 3-A:20B).

A 20-pound dry-chemical (120-B:C) would meet USCG B-III requirements.

USCG ratings go as high as V, which is a big extinguisher on wheels.

Answer 2

According to USCG:

For boats under 26ft

One B-I type approved hand portable fire extinguisher. (Not required on outboard motorboats less than 26 ft in length if the construction of the motorboat is such that it does not permit the entrapment of explosive or flammable gases or vapors, and if fuel tanks are not permanently installed.

For boats over 26 ft to not more than 40 ft

Two B-I type OR one B-II type approved portable fire extinguishers

For boats over 40 ft to not more than 65 ft

Three B-I type OR one B-I type PLUS one B-II type approved portable fire extinguishers.

Answer 3

B-I and B-II refer to the relative fire extinguishing capacity of approved USCG fire extinguishers, depending upon the type of extinguishing agent used.

Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil.

The numerical rating BEFORE the letter B, for class B extinguishers, indicates the approximate number of square feet of fire it can extinguish (i.e., with no significant depth).

The numerical rating (I, II, III) AFTER the letter B indicates Coast Guard classification. For example, a UL 5-B:C, rated for 5 sq ft of liquid fire, would be a USCG B-I extinguisher (with 2 pounds of dry chemical).

To obtain a USCG B-II rating you would need the equivalent of 10 pounds of dry chemical, such as having two UL 3-A, 40-B:C extinguishers, or a 15-pound CO2 extinguisher, or 2 1/2 gallons of AFFF "foam" (UL 3-A:20B).

A 20-pound dry-chemical (120-B:C) would meet USCG B-III requirements.

USCG ratings go as high as V, which is a big extinguisher on wheels.

Answer 4

At least one USCG-approved Class B-1 fire extinguisher is required on any powerboat, unless it is under the following exception:

• "motorboats less than 26 feet in length,
• propelled by outboard motors and
• not carrying passengers for hire, need not carry such portable fire extinguishers if
• the construction of such motorboats will not permit the entrapment of explosive or flammable gases or vapors" [bullets added]

A UL-listed 5-B:C extinguisher, with 2 pounds of dry chemical, may provide the basis for the extinguisher, but it must ALSO conform to USCG-approvals (proper corrosion protection, labeling, mounting bracket, etc).

Answer 5

If your boat is required to have a fire extinguisher, it would have to be a Type B-1, US Coast Guard approved extinguisher, or larger.