Bavarian Belle Riverboat at 925 South Main Street D3, Frankenmuth, Michigan.

My son and I take this cruise every year when we come to Frankenmuth. It is family owned and the guys are great. Definitely a must when visiting here. The captain takes pictures of the wildlife that he sees along the bank and he has them on display.

My wife and I took our two granddaughters on the Bavarian Belle today. The staff where very friendly and helpful. The Riverboat was very clean. I didn't have to use the restrooms but like I said " two granddaughters." My wife said the restrooms where nicer then she thought they would be.
You'll want to get your popcorn early though. The ducks will be running up to the riverboat to help you and kids eat it. Pace yourself , the ducks come up to you through out your family trip.
I would highly recommend doing this as it's priced very reasonable and a lot of fun.