Meeting on the water lifts a seminar or client event out of the usual office routine. Six boats are listed, four of them in Antwerpen, including Flandria, De Ark and Blue Rhapsody. Grace Kelly The Yacht Experience takes 250 guests, and the largest, Oceandiva in Amsterdam, takes 1,500. Five accept groups of 100 or more, and five are also set up as conference venues. Smaller teams can look at MeetDistrict Berchem, with 70 places.