This term means any article or substance which is used on board a vessel subject to the appropriate portions of part 147 of Subchapter N (Dangerous Cargoes) of this chapter for the upkeep and maintenance of the vessel; or for the safety or comfort of the vessel, its passengers or crew; or for the operation or navigation of the vessel (except fuel for its own machinery).
46 C.F.R. §188.10-73