Kayaking along Pictured Rocks National Lakeshore, Upper Peninsula, Michigan. I did this for vacation last year. It's an eight hour day trip along the Pictured Rocks. Breath taking and well worth the money you spend on the experience!
Glass-Bottom Boat Shipwreck Tours | Munising, Upper Peninsula Michigan | "Lake Superiors natural underwater museum featuring a rare, fully intact, wooden sailing ship that was built before the Civil War and sits only a few feet from the surface of the lake."