Dress code info from NCL site https://www.ncl.com/faq#!#what-clothes-should-i-pack
"Cruise Casual: the Freedom of Freestyle Cruising
Dress cruise casual anytime during the day, in the buffet and in most specialty restaurants. For women, it includes summer and casual dresses, skirts, regular or capri pants, shorts, jeans and tops. Khakis, jeans, shorts and casual shirts are fine for men. Swimwear is acceptable at the buffet and outdoor restaurant, but a shirt or a cover-up and footwear are required.
Be sure to pack a sweater — the air conditioning can be chilly. Kids 12 and under are welcome to wear nice shorts in all our restaurants.
Please Note: We want you to be comfortable, but tank tops for men, flip flops, baseball caps, visors and jeans that are overly faded, with holes or tears and worn below the hips are not permitted in main dining rooms or specialty restaurants.
All Decked-out: Smart Casual
Dress smart casual in our more formal dining room or in our more upscale specialty restaurants. For women, it includes slacks or jeans, dresses, skirts and tops. For men, it's jeans or slacks with a collared shirt and closed-toed shoes. Kids 12 and under are welcome to wear nice shorts in all our restaurants."