Tail-Lobbing, Lobtailing, Tail-Slapping all means the same. This action is when an orca slaps its tail against the surface. It can get pretty loud, so some scientists think its probably a method of communication. The whales might also be trying to get rid of unwanted parasites, or they might just enjoy slapping the water! This killer whale is slapping just off the stern of our boat. Note that orca tend to be on their back when tail slapping….