We went on the Ambassador Ambition North Cape and Land of the Midnight Sun in July last year. I was surprised at how many men went for either a tux or suit on formal nights. Although I did take one with me I just dressed in a shirt and tie with suit pants. I was not out of place. Quite a few others did the same and a handful even dressed dressed casually.
I would say on our cruise 2/3 tux or suit, and the rest mainly shirt and tie. Many men lost the tie and jacket after dinner. It's your holiday, if you do not want to wear a tux or suit then don't. I do not recollect any 'smart nights' only formal or casual.
