Yep. It's a standing wave pretty close from the bank right behind H67. People surf there pretty much all year round, summer[1] or winter[2], it's pretty mental seeing them come out of the river with ice picks dangling from their beards.
There's a standing wave in a creek in Munichs central park. It's not an uncommon sight to see people in wetsuit and with a board crossing the central square. Freaks out non-locals every time.
I just thought it'd be a good idea to give a warning as having some unexpected music blast in your ears when you're just there to see a guy surfing a winter wave looks like might annoy some.
[1] https://www.youtube.com/watch?v=krVpLIN7Oxs
[2] https://www.youtube.com/watch?v=36bq5W7tbxE (WARNING - obnoxious music, turn down the volume)