The Grand Mariner coastal cruise ship was tied up Wednesday Downtown along the Northbank Riverwalk. The 184-foot vessel is stopping for a few days for the crew to perform some minor maintenance before it heads south for the winter. USA River Cruises operates the Grand Mariner and offers cruises in Belize, Guatemala and Honduras through March. Next spring and summer, the ship is scheduled for Mississippi River, Great Lakes, Hudson River and New England itineraries.