Depending on the size of your boat you may need more than one. Boats less than 26' have to have at least one B-1 fire extinguisher on board. Boats 26'-40' need to have at least two B-1 fire extinguishers on board.
Graphite is an electric conductor, consequently, useful in such applications as arc lamp electrodes. It can conduct electricity due to the vast electron delocalization within the carbon layers (a phenomenon called aromaticity).
Researchers have found yet another use for the wonder material graphene. A composite material made from reduced graphene oxide and magnetite could effectively remove arsenic from drinking water, according to new work done in South Korea. Graphene is a sheet of carbon just one atom thick that also exists as an oxide. Reduced graphene oxide (RGO) is a chemical state of the material that has gained electrons. The purification process works by dispersing a magnetite-RGO composite in water, where it soaks up arsenic. The composite is then quickly and efficiently removed from the water using a permanent magnet.