Whales slap their tails or lobtail repeatedly as a means of communication, to warn away predators or other males, and to impress a potential mate. Each summer, humpback whales head up to Newfoundland waters to feed on the caplin. Whales plentiful during the summer months between July and mid-August. You can watch them from the shores at Cape Spear or along different parts of the East Coast trail or around the Southern Shore. Once a humpback dives down, it will be another 15 minutes or so before it heads up again.