The saving to suitors clause merely excepts from the exclusive admiralty or maritime jurisdiction of the federal courts all cases in which suits may be brought to obtain other than admiralty remedies to which suitors are otherwise entitled.  Jurisdiction of admiralty court is exclusive only as to those maritime causes of action that are begun and carried on as proceedings in rem — that is, where a vessel or thing is itself treated as the offender and made the defendant by name or description in order to enforce a right.  Therefore, where the suit is in rem, only the admiralty court has jurisdiction.[i]

The foundation of jurisdiction in rem is the taking of the vessel into the custody of the court and the characteristic virtue of a proceeding in rem is that it operates directly upon the res as the so called respondent in the suit and the actual subject-matter of the jurisdiction.  An admiralty court by seizure in rem acquires jurisdiction of all interests in the res and by decree in rem binds all.

However, remedy in rem in cases of forfeiture of vessel falls within the scope of the “saving to suitors” clause, because the common law recognized such a remedy.

[i] Pasternack v. Lubetich, 11 Wn. App. 265 (Wash. Ct. App. 1974)