Yes, I know exactly what you mean by "floaty" feeling.
I feel this way often... almost as if my feet aren't touching the ground, and like I'm in a tunnel (vision gets kind of weird).
When I feel this way, I've learned to concentrate on how I'm breathing. If I am breathing through my chest (instead of lower belly), it could be the carbon dioxide. Sometimes I even breathe into a paper bag for about 5 minutes until the feeling goes away.
I HATE that feeling..for me, it is probably the worst symptom of my anxiety/panic attacks but I am working VERY hard to not concentrate on it when it comes and to overcome it.
I've just got over one symptom to develop another one!! Does anyone know what I mean when I say I feel like I'm going to go all floaty?? I feel like my eyes are going out of focus and my legs etc feel like they get light? I'm not sure if its just where I am tired but of course now I think all sorts is wrong with me! I've got to hand an essay into uni tomorrow and I think I'm anxious about that but I don't want to spend all night worrying about some stupid feeling!! Any help would be gratefully appreciated!!