Bubble Rings

Want to know how ? Sometimes I just spend time underwater making bubble rings. It is so easy to make a perfect circle.

A bubble ring, or toroidal bubble, is an underwater vortex ring where an air bubble occupies the core of the vortex, forming a ring shape. The ring of air as well as the nearby water spins poloidally as it travels through the water, much like a flexible bracelet might spin when it is rolled on to a person's arm. The faster the bubble ring spins, the more stable it becomes.[1] The physics of vortex rings are still under active study in fluid dynamics.

https://en.wikipedia.org/wiki/Bubble_ring