There is no doubt, as stated by the counsel for the appellant, that the jurisdiction of the admiralty extends to all cases of tort committed on the high seas, and in this country on navigable waters. For the redress of these torts, the courts of admiralty may proceed in personam, and when the cause of the injury is the subject of a maritime lien, may also proceed in rem. The latter proceeding is the remedy afforded for the enforcement of liens of that character.
A maritime lien, unlike a lien at common law, may, in many cases, exist without possession of the thing, upon which it is asserted, either actual or constructive. It confers, however, upon its holder such a right in the thing that he may subject it to condemnation and sale to satisfy his claim or damages; and when the lien arises from torts committed at sea, it travels with the thing, wherever that goes, and into whosesoever hands it may pass. The only object of the proceeding in rem, is to make this right, where it exists, available — to carry it into effect. It subserves no other purpose.
The lien and the proceeding in rem are, therefore, correlative — where one exists, the other can be taken, and not otherwise. Such is the language of the Privy Council in the decision of the case of The Bold Buccleugh.
There is an expression in the case of The Volant,
A maritime lien can only exist upon movable things engaged in navigation, or upon things which are the subjects of commerce on the high seas or navigable waters. It may arise with reference to vessels, steamers, and rafts, and upon goods and merchandise carried by them. But it cannot arise upon anything which is fixed and immovable, like a wharf, a bridge, or real estate of any kind. Though bridges and wharves may aid commerce by facilitating intercourse on land, or the discharge of cargoes, they are not in any sense the subjects of maritime lien.