I've been doing a little research for an up-coming Practical Sailor article on firefighting for cruisers.
Fire prevention is the first step. I experienced a number of incipient fires in the refinery over the years and one on a boat and they all shared a common cause; chafed wire or by extension, a bad switch. Two were complicated by running the wires through the same pass-through as fuel lines; common practice, but really dumb.
Fire extinguisher are obvious enough. Mount them where they won't be blocked by the fire and understand that once you use them you will not be able to reenter the cabin to finish fighting the fire due to the fumes the fire extinguisher creates. Funny, they never mention that rather important detail. Additionally, the extinguisher does NOT cool the embers, which commonly reignite the moment the extinguishing media dissipates and the air returns. You need to either keep the air away or cool the embers with water. To keep the air away you need a physical barrier.
I moved on to fire blankets. Not mentioned as often, rare in chandleries, but one of the best proven and simple items. Very difficult to make things worse and it will always slow the progression while you gather more materials. So I went in the basement to gather a few materials for a test; glass cloth, cotton rags, and some scraps of wool. Pulled out a torch and within a few minutes of testing came to an embarrassing "ah-ha moment:"
Army Surplus wool blankets are fire retardant treated and won't burn. Of course they are treated. It's a war.
Wasn't that obvious?
Wool is actually preferred for first responders and most industrial use because it is better for wrapping people and drapes better over the fire. However, fiberglass is common for house hold use because it fits in a smaller package. I'm going to make a cover for the Army blanket and use that. It really would not burn.