The short answer is, no engine? No fire extinguisher. But even that is not 100% complete (see #5 below.)

U.S. Coast Guard-approved, marine-type fire extinguishers are required on boats where a fire hazard could be expected from the engines or fuel system.

Fire extinguishers are required on boats when any of the following conditions exist:

  1. There are closed compartments and compartments under seats where portable fuel tanks may be stored.
  2. There are double bottoms not sealed to the hull or that are not completely filled with flotation materials.
  3. There are closed living spaces.
  4. There are closed stowage compartments, in which combustible or flammable materials are stored.
  5. There are permanently installed fuel tanks. (Fuel tanks secured so they cannot be moved in case of a fire or other emergency are considered permanently installed. Also, if the weight of a fuel tank is such that persons on board cannot move it, the U.S. Coast Guard may consider it permanently installed.)

The subtlety here is that a boat with an engine – but with a small enough portable fuel tank that it could be thrown overboard in an emergency – is not required to have a fire extinguisher aboard.

But you’ll surely wish you had one aboard!