Portrait photography is mostly stills. Photographers take their time to adjust every single detail to ensure that the subject looks her best. You can hear them giving your detailed guidance: "move your chin up, rotate your head clockwise, now look down".
With the advent of fast strobes, fast lenses, and limitless digital capture capacities, sessions became more dynamic, almost a sport. Hold a guitar, jump up, while the camera is going click-click-click at the speed of light. These dynamic images have made the fortunes of commercial photographers.
Underwater, "jumping" is actually the norm, since the subject's feet are often not touching the floor. Swimming and diving are often the most used movements. Below is another one, an upside-down movement by MacKenzie (image was rotated 180 degrees in post-processing).
There is one more element underwater that we use to augment the notion of movement: bubbles! Usually, long hair and flowing chiffons or dresses accentuates the perception of motion; bubbles take it to a whole new level, usually associated with a vertical motion (ascent or descent). I asked Lola to stand up by the side of the pool, wait for me to be settled underwater with my equipment, count to three then jump as high as she can, to make a big splash.
This picture above has garnered lot of attention. Simple execution, but we can't control the elements. Take it or leave it, it is all about repetition and happenstance. On that same vein, still working with bubbles but without a jump, a vigorous swim on the surface is an option. Pool chemistry and aeration plays a role, as well as water temperature. Blame it on the van der Waals forces between water molecules. Or said differently, the coldest the temperature, the more rigid the surface. This photograph below was done on a very cold South Florida day when air temperature was in the 50's. The pool heater was barely able to raise the temperature of the water to the upper 70's that day, which in underwater parlance, is very cold.
