Hi Lee, my last cruise was May 1997. I saw several people during formal evenings wear casual clothing. I can't imagine anyone from the ship telling paying passengers that they have to dress up! I think as long as a person dresses in decent clothes (no torn jeans, shorts, etc. during the evenings) that will be fine. Not everyone has the clothing for several formal evenings. You are paying for your vacation, so be comfortable!

Hi Lee,
I have been on 49 cruises and am a travel agent.
Cruise lines all ask (beg) you to dress up on formal night. If you do not own a tux they advise dark sport jacket and tie (shirt and pants too). Women tend to dress up every night. Casual means sport shirt and slacks (no shorts, T's or halter tops....if you wear halter tops). They frown on jeans, but I see them worn. Teenagers wear anything on hand, any night.
If you do wear a tux, you will make a hit and receive nice comments.
You mentioned "better." I presume "better" is Crystal, Radisson, Seaborne, Holland, Silversea. I would advise you to dress-up. Cruises in Europe or exotic destinations also.
I put it this way to my customers: Would you go to a country-club dance in your sport shirt?
Cruise lines also ask you to wear your tux (jacket) during the entire evening hours. I see less and less cruisers doing this. I also see men going into the dining room in a jacket and it ends up on the back of the chair.
Your best bet would be to ask your travel agent for advice on the dress code for your particular line.

I've been on 20+ cruises, ranging from mid-market (Princess, NCL, RCL, Celebrity) to high-end (Crystal & Cunard). My observation is that the mid-market ships are less rigid with their dress code and "formal" can mean anything from no jacket to a tux. On these evenings, probably only 20% have tuxes, probably 60% in suits and the remaining 20% in less formal attire. The high-end ships are very different - I'd say about 40% in tuxes and 55% in suits and just a few people in more casual wear. I have seen instances where the maitre d' reminded tie-less men of the evening's dress code and offered to hold their table while they changed. Other than that, I've never heard of a cruise line doing any more to enforce the dress code. (I think the - often obvious - disapproval of other passengers is probably more potent than anything a ship would do.)

Paul's suggestion to check with your travel agent for specific examples of the dress code for the ships you're interested in is good. Another idea is to really study the photos in the brochures closely - if they show all those attractive couples "having fun" wearing tuxes, that's a hint. Other brochures will show them wearing suits, etc. Also, check out cruise guidebooks - some of the discuss adherence to the dress codes for each ship.

Good luck!

Lee,
If you don't want to dress up, my suggestion: eat dinner at the buffet, usually Lido deck or order room service. It will save you the embarrassment.

Fran's suggestion is excellent-most cruises now have alternative dining, often with the same food as in the dining room or a buffet style dinner. We didn't want to pack all those extra clothes so we did this several nights, more for the sake of the other passengers that wanted to enjoy the formal atmosphere than to save our own embarrassment.

Most people who cruise on the "better" lines have formal clothing and enjoy the opportunity to wear them. It's one of the things that make a quality cruise different than an ordinary vacation. If you don't like to dress up, you would probably enjoy the more casual lines like Carnival.