Floating to gliding to kicking to front crawl is one progression. Swimming in deep water with your head up, i.e. doggy paddle or treading water, is a separate skill and has to be taught differently. Let me think... In Preschool A and B, the first swimming levels, I teach assisted floats, i.e. the child doesn't have to hold themselves up because the instructor does, but they have to have the correct body position. In order to pass Preschool C, the child has to do unassisted floats on their front and back. In order to pass Preschool D, they have to tread water for 5 seconds in deep water. So that comes after floats, but it's not the same skill exactly, and it's not what progresses into front crawl.