Treading water is what a simmer can do while in a vertical position to keep their head above the surface of the water, while not providing sufficient directional thrust to overcome inertia and propel the swimmer in any specific direction.
Treading water is what a simmer can do while in a vertical position to keep their head above the surface of the water, while not providing sufficient directional thrust to overcome inertia and propel the swimmer in any specific direction.