46 U.S.C. § 31342: Establishing maritime liens

(a) Except as provided in subsection (b) of this section, a person providing necessaries to a vessel on the order of the owner or a person authorized by the owner—(1) has a maritime lien on the vessel; (2) may bring a civil action in rem to enforce the lien; and (3) is not required to allege or prove in the action that credit was given to the vessel. (b) This section does not apply to a public vessel.