So if you can't float you can't swim? I need at least a 3mm full suit to float in fresh water, and a 3mm shorty in salt water. I can swim reasonably well but if you ask me to float without some form of assistance I am screwed. I can tread water, but floating is not something I'm physically able to do. I simply sink, even with full lungs.To 'swim', they need to be able to float on their back and stomach and flip between the two, they need to be able to submerge their face in the water and blow bubbles through their mouth and nose, they need to be able to glide through the water with minimal scuffling of the arms and legs, and they need to be able to make continual forward progression in the water (dog paddle acceptable)
I'm curious what makes floating a prerequisite for swimming, in your opinion. Or are you just saying that a person needs to be comfortable enough in the water not to panic when they are "being still"?