The lighthearted holiday hit seven years Tuesday. It began with two men tubing to work along Boulder Creek in 2008.
Last year, it saw almost 30 participants, some wearing wetsuits and some wearing business suits.
The event typically takes place in June to line up with Boulder's Bike to Work Day. But the Daily Camera reports (http://bit.ly/1qZhv16 ) safety concerns because of the volume of water forced it to be pushed to July this year.
The city of Boulder sponsored a breakfast station off the creek. The public was invited to participate, but commuters were required to bring their own tubes.
Information from: Daily Camera, http://www.dailycamera.com/