Two parties in admiralty actions are claimants and defendants.  Theoretically speaking, in an in rem proceeding, res is the party to the proceeding and not its owner.  However, because the proceedings in rem against the res incidentally affect the persons interested in the res, they have the right to defend against the claim.  Therefore, because the persons interested have the control over the res, they are considered as the parties to the admiralty suit in rem.

In The Mary, 13 U.S. 126, 144 (U.S. 1815), the court held that in case of proceedings against a person, notice is served personally.  Whereas in case of in rem proceedings against a res, the notice is served upon the thing itself.  This service of notice must be considered as notice to all those who have any interest in the thing.  This is a reasonable notice because it is necessary for all those who have any interest in the thing to guard and protect that interest.

Further, admiralty law considers a vessel as a body different from its owner, and so an in rem action to enforce a maritime lien will be brought against the vessel itself and not against the owner.[i]  Therefore, an owner cannot be made personally liable for a judgment against the vessel for an amount in excess of the value of the vessel.

Generally, claimants are persons who make a claim on the property proceed against which is similar to libellant against the thing libeled.  But the libellant sues generally for his/her personal claim, while the claimant can only defend a thing in which s/he has an interest, and cannot be heard beyond the interest which s/he has therein.[ii]  The claimant is really an intervener in the litigation who asks for his property and agrees to secure the libellant to the extent of the amount in suit, or, to the extent of the value of the vessel as agreed between the parties or fixed by the court on appraisal.

However, claimant is different from an ordinary intervener.  Claimant in a suit in rem emphasizes his/her interest in res as well as right to possess the res, and the right to provide security for preventing the sale of res.[iii]  Further, in Lottawanna, 87 U.S. 201 (U.S. 1874), it was held that a person who merely has a collateral interest in a question involved in the suit and has no active concern in the res, cannot be a party to an admiralty suit in rem.

[i] P.R. Ports Auth. v. Barge KATY-B, 427 F.3d 93, 105 (1st Cir. P.R. 2005)

[ii] The Manhattan, 181 F. 229, 236 (D.N.Y. 1910)

[iii] The Ruth E. Merrill, 286 F. 355, 356-357 (2d Cir. N.Y. 1922)