the more water an animal's fin pushes against, the faster that animal will move through water
running_water is moving_water. backstroke is moving_all_legs. traveling_rapidly_across_water is traveling_rapidly. when_ducks_move_across_water is in_water. white_water is fast_flowing_water. perf is river. waves is moving_water. heavy_water is water. moving_water is running_water. horse is very_fast_animal.