Why are B-III fire extinguishers particularly suitable for certain vessels?

B-III fire extinguishers are particularly suitable for certain vessels because they contain a specific type and amount of extinguishing agent that is effective for combating flammable liquid fires, such as those that may occur in marine environments. The designation "B" indicates that the extinguisher is suitable for flammable liquids, while the "III" signifies that it is meant for use on larger fires within that category, making it particularly useful for commercial vessels where flammable materials are present. This specific composition ensures that the extinguisher can effectively suppress fires from substances like gasoline, oil, or hydrocarbons that are more prevalent in boat operations.

The other options do not provide the same level of context or specification needed for the unique fire risks faced on vessels. For instance, while weight can be a consideration, it doesn't address the efficacy of the extinguisher in a fire situation. Similarly, while other varieties of extinguishers may be designed for specific areas or may boast factors like shelf life, these attributes do not target the unique needs of combating flammable liquid fires commonly encountered on boats and vessels.