To create the bubble ring, the dolphin first uses one of its flippers to create a spinning ring of water called a "vortex ring." Next, the dolphin blows a giant air bubble directly into the ring. As the air bubble increases in size it's flattened by the weight of the water above it. As more air is blown into the bubble, water seeps in as well. The water seeping in from below eventually forms a fountain that shoots through the center of the bubble. When it breaks through the top of the bubble, a ring of air is left behind, held together by the force of the water spinning around it. It's so stable in fact that it can be broken apart into smaller rings, which can then be inflated to form larger rings.