The Collaborative International Dictionary of English v.0.48:

Embarkation \Em`bar*ka"tion\, n.
   1. The act of putting or going on board of a vessel; as, the
      embarkation of troops.
      [1913 Webster]

   2. That which is embarked; as, an embarkation of Jesuits.
      --Smollett.
      [1913 Webster]

WordNet (r) 3.0 (2006):

embarkation
    n 1: the act of passengers and crew getting aboard a ship or
         aircraft [syn: boarding, embarkation, embarkment]
         [ant: debarkation, disembarkation, disembarkment]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "embarkation":
   boarding, coming out, curtain raiser, debut, disembarkation,
   embarkment, emplanement, enplanement, entrainment,
   first appearance, floating, flotation, hopoff, inaugural address,
   inauguration, induction, initiation, installation, installment,
   introduction, launching, maiden speech, opener, preliminary,
   takeoff, unveiling