Inflatable fabric for a D tube

I'm looking for a fabric to hold air when inflated at a low pressure (2-4 lbs.)It will mount to the sides of a boat but above the waterline by about 10". Unlike an inflatable it will not be constantly bouncing off of the water. It needs good UV protection and will provide added floatation protection. Will be mounted to the boat sides top and bottom with SS snaps or twists. Hypalon is out of the picture as are certain rubber products due to high cost. An 18" D tube with a 9" radius, 10' long will hold up approx. 548 lbs. Any ideas on fabric types
and experiences will be greatly appreciated. Thanks, Stan PS When deflated, boat will be the legal limit to trailer.

 

Does anyone have any suggestions for me, or experiences? Thanks much.

 

Hypalon or pvc.

http://en.wikipedia.org/wiki/Hypalon

 

http://www.dupontelastomers.com/products/hypalon/hypalon.asp?redirect=hypalondotcom

 

I have built 10"dia tubes for air bag presses out of 18 oz pvc fabric as used for semi trailer tarps, we used massive end clamps and ran 100 psi. We used an adhesive called HH66 with a 10" overlap seam but clearly you would need much less with low pressure. The material was availabe locally from places that made tarps in an array of colors, obviously it is ok with UV.

Steve.

 

Hoyt and Steve W, thanks. I am looking over the 18 0z. pvc fabric and I love the price.
Also like the color range. I appreciate the help guys. Stan

 

I think that the PVC that roofers use is the same stuff. Basically, flexible PVC with polyester cords inside. Can be heat bonded or with HH-66. A few have Evaloy for greater life.