The river is in perfect shape for a float. There is stringy green algae washing downriver intermittently, but it shouldn't prove much of a bother unless you're throwing crankbaits.
I would throw a pearl or white swim jig or spinnerbait and concentrate on the edges of structure in current. This could be logs, outside turns, drain pipes, bridge pilings, stream barbs, edges of islands, etc. Current is key. Put your bait in the right area and a smallie should pounce on it. I wouldn't hesitate to toss a buzzbait along bridge pilings, rock walls, etc. Bring it downstream and clack the structure.
Plastics are fine but IMHO you need a search bait for this type of long float with many spots to hit. Have a plan if a storm and/or lightning rolls in. Geneva to Aurora is a hefty stretch. Get creative on your angles and what spots you hit and I'm sure you'll find some fish. A 15" seems to be an "average" big one lately. Lots of 13"-14" while throwing larger baits. If you nail an 18" or better on a Saturday while exploring, that's exceptional.
Wear sunscreen, keep skin covered as much as you can. Bring plenty to drink. Get out and stretch from time to time. Use a paddle leash to keep your paddle secure. Narrows and shallower areas will be swift.
And of course, wear a life jacket.