The Collaborative International Dictionary of English v.0.48:

Debarkation \De`bar*ka"tion\, n.
   Disembarkation.
   [1913 Webster]

         The debarkation, therefore, had to take place by small
         steamers.                                --U. S. Grant.
   [1913 Webster]

WordNet (r) 3.0 (2006):

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