In my decade of living in Chicago, I have covered the annual dyeing green of the Chicago River in celebration of St. Patrick’s Day almost every year — twice in my two years with the Associated Press. Every March, the Chicago Journeymen Plumbers Local Union 130 deposits their secret recipe of what they call “leprechaun dust” in the Chicago River in front of thousands of spectators.

Like many other Associated Press photographers, I try to look for new ways to photograph assignments I’ve done many times. I have covered this event from the shore, from the tops of tall buildings, from bridges and from boats. This year, videojournalist Melissa Perez Winder and I secured a choice spot on the riverwalk area, squeezing in with green-clad onlookers, eager to catch a look at the river turning an emerald hue.

The dye is released from hoses on two large boats and as orange powder from smaller vessels. The orange powder turns green when it comes in contact with the water. From experience, most of the activity takes please near the DuSable Bridge where we stationed ourselves, so I knew it would be a good vantage point. We waited patiently until a little after 10 a.m., when horns from the boats blew loudly and the river started changing from its natural color to something resembling lime Jell-O. The most interesting pictures of this process, in my opinion, happen somewhere between the first glimpses of green to when the river is fully mixed. The liquid and powder dyes swirl in the water with each turn of the boats, creating beautiful, abstract art that is seen in this photo.

I made this photo with a Sony A9 III camera and 24-70 mm 2.8 lens. My slightly-elevated viewpoint above the river shows the swirls and sprays in the water as the large boats dance around each other, and the many onlookers surrounding the spectacle on the shores and bridge.

I admit that this Chicago tradition naturally lends it self to beautiful, colorful images, but experience and pre-planning lead to this one — one of my favorites of the day and one of my favorites of a decade of imagining the St. Patrick’s Day tradition.