Their is no consensuses amount the scientific community for tail slapping or lobtailing by humpback whales. The reasons range from communication to feeding habits. In our viewing area of the Johnstone Strait it seems to occur more often on days with a little chop on the water. The reasons is not as important as the fact that it happens three or four times a week and is always spectacular. And even more attention getting is that it is often accompanied by breaching.