During my days as a ship's engineer, I saw a few systems for fire suppression. It was, if my memory serves me correctly, a requirement to have a fixed sytem to protect the machinery spaces on board.
Older ships had a steam smothering system which would I suppose be quite effective in putting out the flames, but hardly a good environment to move around in.
Slightly more up to date was the CO2 smothering systems. This consisted of a room with row upon row of large CO2 bottles. Opening the activation box would sound a warning siren to make sure the machinery space was evacuated. More modern systems would have a refrigerated tank to hold the CO2 which was a smaller neater installation.
The most modern ships I worked on (at least 20 yrs old now) had a Halon system. As stated above, it is possible to survive in a Halon atmosphere sufficiently dense to extinguish the fire. Lord knows what the release of several cubic metres of Halon does to the ozone layer.
There were also fixed foam systems, Hi expansion foam systems and Aqueous Film Forming Foam systems.
I believe now they have gone back to CO2 and Halon substitutes such as HFC-227ea
As a matter of interest, does anybody know why fire extinguishers have gone from being nicely colour coded so that the type of extinguishant was patently bleeding obvious, to making them all red?
Doubtless some sort of EU ruling?