That is fine if he is comfortable in it. A little overdressed for some because they are usually "Casual" nights. Most men will be in Docker type slacks and a Polo, button down OR Hawaiian print shirt. Any type with a collar, but just no t-shirts for the dinner time.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean
Cheryl-Beth- casual night attire for men is basically Dockers type pants with a polo, hawaiian print or button-down shirt, and casual shoes.
Dress shirt and tie would be a bit overdressed for casual nights.
Hello Friends, Carnival prefer that you don't wear shorts and/or gym clothes, or beach attire to the dining room. Other than that, business casual is what I've mostly witnessed on my past 8 cruises in the dining rooms. You can pretty much wear what you want if it doesn't gross out the other passengers while they are eating. Men wear suit jackets and ties to the formal night dinners. Not to worry if you don't have a jacket and tie they won't through you over the ship. It's just a nice time to dress up and SMELL GOOD!
For men on the non formal nights in the diningroom......... is pants with a shirt and tie ok? No jacket.
The prescribed attire varies from one cruise line to another and what people actually wear on a particular line may vary from one destination to another. On Princess Cruises, all nights except the formal nights are "smart casual" -- which basically means that gentlemen wear a polo shirt, golf shirt, sports shirt, or Hawaiian shirt with slacks, socks, and dress shoes. A dress shirt and tie and a sport coat or a business suit are optional. On Celebrity Cruises, some nights are "casual" -- same as above -- and others are "informal" -- meaning that a sport coat is necessary. Your pre-cruise information package should contain more detailed information on the number of evenings for each prescribed dress and the corresponding attire.
I have observed that passengers on cruises to the Caribbean, the Mexican Riviera, and Alaska tend to be more lax in observance of the prescribed dress than passengers on cruises to other destinations. For better or for worse, these destinations seem to draw a lot of "first time" passengers who don't read the pre-cruise information very carefully and thus do not bring the proper attire.