On formal evenings, women wear everything from party dresses to glittery gala gowns. Men generally opt for dark suits rather than tuxedos, though Costa has a convenient tux rental package. There are two formal nights on a seven-night cruise. Other nights in the Caribbean are casual, the ultimate in casual being the last night's Roman Bacchanal when the crew hands out bed sheets to be worn as togas. I was surprised to see that only half the passengers participated. A number of past Costa passengers went all out, bringing their toga gear from home.