..........amusement park in America for the 9th straight year is Cedar Point
(http://www.cedarpoint.com/ ) in Sandusky, Ohio as rated by 'Amusement
Today' (http://www.amusementtoday.com/).

Have you ever been to Cedar Point? I have, and for the past 45 years. ;-)

Connection to boating: Cedar Point has a marina and a nice transient
dockage area. Transient boaters have access to the marina pool and
restrooms/showers. There is also a special boaters entrance to the park
that allows for entrance one hour before the park opens.

When our kids were younger (pre college age) and we had the 32 or 27 footer
we would kick off our boating cruise vacation by spending the first
day/night at Kelley's Island, then 3 days at Cedar Point (transient dockage
that was then located adjacent to the Millennium Force roller coaster).
From there we would head to Leamington, Canada for some peace and quite
after hearing the park noise for 3 straight days. ;-)