nontank vessel
(26) “nontank vessel” means a self-propelled vessel that— (A) is at least 400 gross tons as measured under section 14302 of title 46 or, for vessels not measured under that section, as measured under section 14502 of that title; (B) is not a tank vessel; (C) carries oil of any kind as fuel for main propulsion; and (D) operates on the navigable waters of the United States, as defined in section 2101(23) of that title;