(a) Vessels subject to seizure and forfeiture
Whenever any vessel which shall have been built, purchased, fitted out in whole or in part, or held, in the United States or elsewhere, for the purpose of being employed to defraud the revenue or to smuggle any merchandise into the United States, or to smuggle any merchandise into the territory of any foreign government in violation of the laws there in force, if under the laws of such foreign government any penalty or forfeiture is provided for violation of the laws of the United States respecting the customs revenue, or whenever any vessel which shall be found, or discovered to have been employed, or attempted to be employed, within the United States for any such purpose, or in anywise in assistance thereof, or whenever any vessel of the United States which shall be found, or discovered to have been, employed, or attempted to be employed at any place, for any such purpose, or is anywise in assistance thereof, if not subsequently forfeited to the United States or to a foreign government, is found at any place at which any such vessel may be examined by an officer of the customs in the enforcement of any law respecting the revenue, the said vessel and its cargo shall be seized and forfeited.

(b) "Vessels of the United States" defined
Every vessel which is documented, owned, or controlled in the United States, and every vessel of foreign registry which is, directly or indirectly, substantially owned or controlled by any citizen of, or corporation incorporated, owned, or controlled in, the United States, shall, for the purposes of this section, be deemed a vessel of the United States.

(c) Acts constituting prima facie evidence vessel engaged in smuggling
For the purposes of this section, the fact that a vessel has become subject to pursuit as provided in section 1581 of this title, or is a hovering vessel, or that a vessel fails, at any place within the customs waters of the United States or within a customs-enforcement area, to display lights as required by law, shall be prima facie evidence that such vessel is being, or has been, or is attempted to be employed to defraud the revenue of the United States.