WordNet (r) 3.0 (2006):

weigh anchor
    v 1: heave up an anchor in preparation for sailing [syn: weigh
         anchor, weigh the anchor]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "weigh anchor":
   board, break ground, cast away, cast loose, cast off,
   cat the anchor, detach, disengage, doff, drop the mooring, embark,
   embus, emplane, enplane, entrain, free, go aboard, go on board,
   go on shipboard, liberate, loose, loose for sea, loosen,
   put to sea, release, remove, take off, take ship, unbar, unbind,
   unbolt, unbuckle, unbutton, unchain, unclasp, undo, unfasten,
   unfetter, unglue, unlace, unlatch, unleash, unlock, unloose,
   unloosen, unmoor, unstick, unstrap, untie, up-anchor