BOULDER, Colo. (CBS4) – Friday is the ninth annual Tube To Work Day in Boulder. Begun by two men in 2008, attendance jumped to over 200 participants in 2015.

Participants should bring their own tube to Eben G. Fine Park, the Boulder Creek drop in point. A helmet and closed toed shoes are mandatory, and a wet suit recommended.

READ MORE: United States Issues 1st Passport With 'X' Gender Marker For Dana Zzyym Of Colorado

(credit: CBS)

(credit: CBS)

A Facebook page holds all the details, including an update on the creek: flow is low so tubers can expect mellow waters, “longer commute times,” and perhaps more rocks.

READ MORE: Even After Tuesday's Moisture, This October Remains One Of Denver's Driest On Record

(credit: CBS)

(credit: CBS)

In the spirit of discouraging the use of a personal, a shuttle service is available from a parking lot at 4780 Pearl East Circle beginning at 7 a.m. The commute begins at 8.

MORE NEWS: Firefighter Larry Wyant Dies While Battling Eastern Colorado Grass Fire