Old lock and damn #18! Oquawka, Illinois represent!!! LOL!!
I was in Oquawka, IL (which is directly across the river from Burlington) when Pepe, Jacque Custo's lifetime buddy and dive partner came in and said "I ain't going down there no mo'", he said he was at the bottom of the river at the base of the damn with Jacque and he cleared his mask in the muddy water to be looking directly in the face of catfish that was at least 5 times bigger than he was! Pretty funny to hear and see!
To answer you question, no, you won't find many boarding the mighty Mississippi, it's usually really rough and the muddy water hides all sorts of bad stuff, the same goes for backwaters. It can be done but it ain't no fun!
I think you can still wakeboard on Rathbun Lake, it's about 90 miles west. There are other small lakes that you can go to also, but nothing spectacular. I think some wakeboard the Mighty Mississippi by Fort Madison or Nauvoo in the flats but not many.
OBTW, I am from Monmouth, IL and had my braces done in Burlington when I was a kid.