Pursuant to Fed. R. Civ. P. 14(c), if the case is brought on the “law side” of the court, the distinctive rule governing third-party practice in admiralty and maritime cases is not applicable.  However, a defendant in a nonmaritime civil action can utilize the usual rule governing third-party actions to implead third-party defendants whose liability is purely in admiralty.[i]

[i]Canale v. American Export Lines, Inc., 17 F.R.D. 269 (D.N.Y. 1955)