The Collaborative International Dictionary of English v.0.48:

Shipman \Ship"man\, n.; pl. Shipmen.
   A seaman, or sailor. [Obs. or Poetic] --Chaucer. R. Browning.
   [1913 Webster]

         About midnight the shipmen deemed that they drew near
         to some country.                         --Acts xxvii.
                                                  27.
   [1913 Webster]

   Shipman's card, the mariner's compass. [Obs.] --Shak.
      [1913 Webster]