Photo: Aerial performance by Alie Vidich and Evan Hoffman at Invisible River 2013. Photo courtesy of Invisible River.

On the banks and surface of Philadelphia’s Schuylkill River on Aug. 29, the flowing water will come to life with the movement of dancers, boats, musicians and more. This date marks the third iteration of Invisible River, a multimedia performance and festival aimed at bringing attention to the Schuylkill River and Philadelphia watershed. Funded in part with a $25,000 grant from Knight Foundation, the free public art and boating festival takes place on and above the water, as well as in neighboring Fairmount Park.

This year’s river arts festival is scheduled for 2-8 p.m.–twice as long as activities have lasted in previous years, when the duration of the event was three hours instead of six. Food vendors will occupy the nearby banks, and local brewery Sly Fox will operate a beer garden there as well.

To kick off Invisible River 2015, Positive Movement & Ecstatic Drill Team will lead a processional starting at Mander Recreation Center at 33rd Street and Diamond Drive. The drumline will travel down Boxers’ Trail to the Schuylkill waterfront.

From here, attendees may take a boat out onto the river and learn to paddle, or participate in a number of interactive art installations on and about the river. Festivalgoers may rent boats or bring their own, and a limited number of free seats on dragon boats will be available the day of the event on a first-come, first-served basis. (For more information, visit the boating page on Invisible River’s website.)

As evening draws in, the finale will begin in the water, and also from above it, where aerialists suspended from the Strawberry Mansion Bridge will spin and contort themselves as they hang just over the rippling river. Amidst this scene, there will also be some 20 stand-up paddle board dancers, ultimately turning the generally placid waterway into a flurry of movement and action.