Oh just asking I have one of Shawn Mackey's BadCats 10 foot. I know his 10 foot tubes are 21" diam and his frames are top notch built solid. I know the odc are so so but i know a lot of people that bought them say they wish they saved up and bought a skookum or badcat. I love mine just need to find a buddy to float pontoons with.

2 people on a 20" 12' tube in white water seems like it would run deep and be very tippy
21" 10' is perfect for 1 person sits real high in water. Wish i would have gone 12' though so I could run a bigger cooler and more gear but that will be down the road soon.