Cruise ships have been in Lake Michigan (as part of a Great Lakes cruise) for the last 20 plus years.....big and small. Blount Small Ship Adventures has three that may or may not be on in some combination during a given year....185 foot or so, Grande Mariner, Grand Carib and Niagara Prince. Pearl Mist, owned by Pearl River Cruises, a brand new 350 footer has been on this year as had the 450 footer Hamburg of Plantours, a German company...at least one new operator is scheduled on the Lakes next year with runs to Chicago....As many of these ships enter and leave smaller harbors and there is a tendency for small fishing boats to school around the entry ways, it is a good thing to keep clear of the cruisers.....regardless of the legalities of any given navigational situation, in the end big boat always wins....and by the way as I occasionally do some work on the cruisers, passengers are fascinated by the fishing fleets....