What is the inner circumference of the tube? September 18, 2024 01:41 Updated Tubing at Vail is only offered as part of our summer operations. The inner diameter is roughly 20" at the center. Related articles Are your activities good for kids and adults? What dates will the gondola be open for scenic rides at my local resort? How fast do the tubes go down the hill? Do you have disc golf in the summer? Is there a fee? What time do I need to arrive for ski school?