In Rem

An action in rem is a proceeding against the ship itself as the named defendant, the procedural mechanism that lets a claimant arrest the vessel to found jurisdiction and obtain security. It is the distinguishing feature of admiralty practice and the means by which a maritime lien is enforced, since the lien attaches to the res and survives a sale. English law treats the in rem claim as also reaching the owner personally once the writ is served; US practice keeps the in rem and in personam claims more sharply separate.