A male Humpback whale (Megaptera novaeangliae) calf playing at the ocean surface. The calf had just lifted its caudal region out of the water, then flipped over so that his belly was facing upward while he spun his body around. This had the effect of whipping his fluke in a circle, leaving a wake of bubbles, froth and whitewater. This type of play behavior is typical among healthy humpback whale calves. Vava'u, Tonga, South Pacific. September.