My family is spending 2.5 days in Antwerp in mid-March and we're saddened to discover that Flandra--the boat tour company TA recs--is closed until April. We know we're traveling in the off-season, but these tours are available in Bruges and Amsterdam during that same time period, so we were surprised. Is there another tour company anyone could recommend? Or another way to see the Harbor? We're very disappointed.