Basically anything is fine as long as you are comfortable. You will have 2 night where you need to dress really nice( formal nights). The other nights I think we should all dress appropriate for dinner every night like Carnival or any other cruise ship ask, even they don't pressure us if we don't. We'll only doing it for ourselvies. Lets keep some standards here and not wear shorts to dinner, we can do that when we arrive back home. Just mt opinion though. Have a safe cruise all.