Choice is as easy as ABC
Unless you're only using it as a backup, forget Halon. First of all, they're useles against electrical fires (remember the (on)fire truck?), and as another pointed out, they're only truly effective in confined spaces, not up on deck. Halon was designed for, believe it or not, food preparation, so that after putting out a REALLY well done steak, the gas disperses, with no residue to ruin the food. Another downside is, it's bad to breathe, and being invisible, hard to avoid. Same thing with Co2. ABC not only works on all types of fires, some have additives so that the dry chemical sticks to hot surfaces, preventing rekindling. Try knocking down a burning fuel spill with Halon, even on a calm day. ABC will lay on the surface, and keep the fire out. One down side, ABC is very corrosive, so clean up will need to be timely, and invasive. Try going to a local volunteer Fire Department, and asking if you can purchase several expinguishers of different sizes through them. You should also be ale to have them inspect and recharge them as well. Some Dept.s might even let you practice on a controlled fire with any partially discharged extinguishers they have.
