Except for the operation of certain fishing vessels, the operation of all vessels satisfying the requirements of paragraph (f)(1)(i) or (1)(ii) of this section will be deemed "commercial waterway transportation," regardless of whether the vessel is actually engaged in the transportation of property on a particular voyage. Thus, "commercial waterway transportation" includes the operation of vessels while moving empty of cargo, while awaiting passage through locks, while dislodging vessels grounded on a sandbar, while moving to or from a repair facility, while maneuvering around loading and unloading docks, and while fleeting barges into a single tow.
26 C.F.R. §48.4042-1