Kayaker surfing

We have three well-known standing waves in Munich, on which surfers surf with their surfboards.
https://en.wikipedia.org/wiki/Eisbach_(Isar)

Today I stood on the Maria-Einsiedl footbridge and could watch on another standing wave below the raft slide, how not surfers surfed, but kayakers....

See also
https://en.wikipedia.org/wiki/Playboating