A class ABC which is an all purpose (Monoammonium phosphate) dry chemical fire extinguisher. Probably a 20# capacity within 25 feet reach lets say or minimum two 10# ABC extinguishers which are easier to handle weight wise. A class D (Sodium Chloride or Graphite chemical) fire extinguisher for burning metals may also be appropriate given the scenario here regarding a vessel with a fuel tank. If a fire gets hot enough to burn metals nearby, this class D type works wonders.
Class B
Flammable fuels require a class B fire extinguisher.
Class B
Class B
Class B
B-I or B-II are required.
Class B
Unplug all electrical equipment
Carbon Dioxide or foam.
The people onboard the vessel and the ship crew
Class B
Motorboats with permanently installed fuel tanks must have at least one B-I extinguisher. Boats over 26 feet may require more. B-I is either 2 pounds dry chem, 4 pounds CO2 or 6 quarts foam.According to US Coast Guard regulations. 46 CFR 25.30.