I'm not sure what it's called but it's the mesh fabric that football jerseys are made of you, you know, the little tiny holes everywhere?
I found this at http://www.joann.com/power-mesh-many-colors/zprd_10655256a/ but it reminds me of what "tummy control" panels are made of. Other than that, they have utility camo mesh (prob. for like mosquito netting/face covers or hunting blinds?) and decorative sheer stuff.
WalMart has pool floats that are spring loaded, you only air up the outer edges/pillow and the center is this mesh fabric, they are nearly $20 and much nicer than just vinyl ones as you sink into the water when you lay in the center but the rim holds you up. Every one we've had, has a small leak so they don't stay aired up day to day and since the air chambers are inside nylon fabric, you can't patch them.
I think I can make them and instead of air chambers, use channels for those jumbo pool noodles which are quite bouyant and slide them in to make a ring around the fabric. Foam pipe insulation would also work and may be a cheaper alternative to the pool noodles. Depending on cost of fabric, I just might try it. I also thought about shower curtain material but it would not let you sink down in the center.
Kathy