In January 2006 while visiting Antarctica, we witnessed a most unusual method for orca to dislodge a crabeater seal from an ice floe - they made large waves to wash the seal off the relative safety of the ice. Later the orca put the seal back on the ice and dislodged the seal a second time which suggested strongly they were training their young.
A brief preview of a longer video. Orca used a unique technique to dislodge a crabeater seal from an Antarctic ice floe - they created a wave to wash the seal off.