Happy St. Patrick's Day! Tens of thousands of spectators cheered as the Chicago River was dyed green in honor of St. Patrick's Day this past weekend. If you missed it, here you go.

It's been a tradition for over 40 years. Thanks to members of the Chicago Journeymen Plumbers Union who have been turning the river a bright emerald green for years. The secret to success is simply dumping a secret concoction off the sides of motorboats.

According to FOX32 Chicago, this video posted on YouTube was posted by Kurt Miller and is perfect to watch on St. Patrick's Day. Enjoy.