A claimant’s right to challenge the legality of the warrant of arrest under which the vessel was detained, cannot be waived by giving of security.  Admiralty favors stipulation.  So in The Roslyn, 1877 U.S. Dist. LEXIS 38 (S.D.N.Y. 1877), it was held that the validity of the bond or stipulation does not depend upon whether or not the vessel was actually in custody at the time the stipulation was given.

The jurisdiction of the court, on the giving of such a stipulation, to continue with the cause to a decree and to implement the stipulation according to its terms, has never been doubted.  Therefore, the party can waive the process of actual arrest by giving security specified in the plaintiff’s complaint.  Such case of entering a general appearance and giving a stipulation to abide by a decree is deemed to be a waiver of all objections based on an omission to serve the process.  However, in such a case the claimant cannot emphasize the failure to arrest as a ground for avoiding the court’s jurisdiction in rem.[i]

[i] The Roslyn, 1877 U.S. Dist. LEXIS 38 (S.D.N.Y. 1877)