Just received our travel documents for the Westerdam Baltic cruise out of Copenhagen on July 20-30. They state that there will be 3 formal nights, 2 informal nights and 5 casual nights. Does this mean that it would be appropriate to wear my tux on three nights, or is there one "more formal" of the three for that? I have my own tux, but am wondering about bringing another suit or jacket. My wife and I do enjoy dressing for dinner.