Source : Webster's Revised Unabridged Dictionary (1913)

Debarkation \De`bar*ka"tion\, n.
   Disembarkation.

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

Source : WordNet®

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