I decided to add this little section to the previous topic because it really wouldn't fit into a normally asked question. It is something that I will often bring up on board when chatting with a customer. It does have to do with the ratings on the extinguishers.
I so very often see well intentioned manufacturers who do outfit the vessels with the appropriate number of fire extinguishers. However, they are also very often the small little white dry chemical extinguishers that are found on your wave runner. Most are only B:C types even when used in accommodation spaces where the hazard is overwhelmingly class A type materials. Those really small B:C types frequently have 1.5 lbs of powder in them and have a 5 B:C rating. To put that into perspective, I will usually lay the extinguisher across my two cupped hands as if holding two heaping handfuls of powder because that's about what you've got in that extinguisher. A 5 B:C fire is about the size of a typical welcome mat. That extinguisher is rated to put a fire out in a small bathroom-type trash can (forgetting that it has no A rating ).
In the early years of my career I use to service the fire extinguishers at an auto wrecking yard. One day the owner really laid into me in front of a bunch of customers saying that my service was such a rip-off because his (10 Lb dry chem) extinguishers never worked- every time he had a car on fire he could never put it out with "one of those things". I had to calmly explain to him in front of his customers that when a car is on fire, you need a fire TRUCK! this is not some magic fire hydrant that continuously shoots magic fire pixie dust until the fire goes out! They have a limitation- the rating is a notice of the extinguishers limitation- not its ability.
Keep that in mind and think anew about the size of the bilge area in your engine room. Are you really prepared with the proper tool to put out a fire down there? You often will not have a direct "shot" at the base of the flames. The expert operator at the UL laboratory gets to use his extinguisher under the most ideal conditions on the floor of the air conditioned laboratory. There is perfect lighting, no noise, no fans, no fumbling trying to get the extinguisher out of a closet or out of a marine-type bracket, etc. I think in MOST cases out there in the real world those cute little white extinguishers are providing a false sense of security at best and simply satisfying the basic minimum requirements at the least.
You CAN extinguish a fire with the proper tool. Without the proper tool, quite simply put, you CAN'T.
Maybe you need one of these?
This is a 45 litre foam unit. These are required for certain Red Ensign Group vessels subject to MCA requirements.