Being a Wausau resident, I have spent a lot of time casually paddling the Wisconsin River at various points in town. There are 2 dams in the area that restrict a portage-less long trip, but there are still plenty of opportunities. The waters are suitable for entry level paddlers and the scenery is enjoyable enough for the more seasoned to return. Canoe and kayak paddlers will enjoy being alone or with the whole family.
There are 3 major sections of the river that can be paddled in the Wausau area: North of the downtown dam (This is where the Whitewater park is, by the way!), Between the downtown dam and the Rothschild Dam, and South of the Rothschild Dam. On a side note, the Rib and Eau Claire Rivers also offer scenic opportunities and empty into the Wisconsin river in Wausau.
Just North of the Downtown Dam holds a lot of town history as you can see old pilings of saw mills just off the Barker/Stewart Island shores. The island has a nice walking trail that displays information about the old mills. There are 2 main options of putting in, one on each side of the river and in close proximity to one another. The West side offers Schofield Park off of East Randolf Street. There are some baseball fields, picnic area, and playground equipment. The East side features Gilbert Park (about a half mile north of Schofield Park) with a fishing deck and walking path. The shore is a little rocky but there are places to launch a kayak besides the normal boat ramp. Going north from either of the locations, you will see several fern-covered islands, a few small sandy beaches, and on the East shore, some rock cliffs. I enjoy zig-zagging around the islands and seeing the turtles, beavers, and other wildlife.
Between the Dams lies probably the most paddling opportunities the town offers. There is, of course, the whitewater course, which is only available at certain times (Contact: wausauwhitewater.org) and requires special permission, and is worth seeing.
Below the Whitewater course begins a beautiful section of the river that seems less part of the city as it actually is. Riverside and Fern Island parks outline this section of the river and paddling around picnic, fern, and oak islands is a beautiful time in itself. A boat landing at Fern Island Park is the best place to put in here. In the warmer weather, you'll almost always see people swimming on the sand bar just south of the main island (and just north of the Thomas Street bridge). There are alot of great fishing spots too.
Further downstream is Memorial park and is my favorite place in town for putting in. A bay offers the ideal kayak launch area and has parking less than 200 feet away. Coming out of this bay, a paddler can go north to see the islands or do some fishing, or go south into Lake Wausau, the reservoir created by the Rothschild Dam. It is also a great way to paddle over to Rib River and see the cattails and other grasses growing in the lake. Go south, past the airport, and there's another great set of islands and the golf course.
South of the golf course, another great sport for putting in is the landing off of Kort street. There's a nice dock here and shores are great for launches as well. There's a lot of weed growth in the water here in late summer, but with the view of Rib mountain off to the west, Sunsets are beautiful in this area of the river. A culvert under country club road is a fun shortcut to take to the islands north of the Golf Course.
Launching South of the Rothschild Dam is easy once you've found the landing. If you like Bass fishing, this is a great stretch to be in. The landing is accessible from Sunrise Drive. From the interstate (51), exit at Rib Mountain Drive and go North to Morning Glory Lane, Turn Left (East) and follow it as it turns to Mayflower Lane, Lilac Ave, and finally, Sunrise.
You will see motor boats on all of these section of the River but less so in the northern half of the area between the dams, which is also probably the most scenic. The whole river does not feel like it flows through a city. It is very quiet and full of scenery and wildlife. You'll also likely see other friendly paddlers out there. It's a great place for the family.
Again, I recommend Memorial Park (off of Sturgeon Eddy Road) as your launch point. A short trip north to the islands will be a neat afternoon trip. Bring your fishing tackle, swim gear, and camera!
No fees or permits are required.
Wausau is located at the intersection of Highways 51 and 29 in Central Wisconsin.
All launch points described above are in public parks and no fee is required for non-motorized boats. There are regular launch ramps but the shoreline is usually better.
Google Earth has a high resolution coverage of the area and there are some user-community photos posted that will give you an idea if what you will see.