He'll be fine! As long as he has a jacket or a tie, it'll be fine. Many times when I cruise I don't want to hassle with the weight of a jacket, so I'll just wear a tie and even on Holland America or Celebrity, which are a bit more formal than RCCL, I've never had any problems.
So tell him to relax and enjoy the cruise!
__________________ Travel Agent/Cruise Specialist w/12 yrs exp and 47 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!
A shirt with a tie will be fine. Sometimes it is too warm in the dining rooms for a jacket, so my guys will wear a nice shirt and tie. They sometimes wear a nice pair of dark jeans (usually new or black) instead of dress pants. We were on Princess once and the men were required to have either a tie or a jacket. I don't remember ever having to have either on Royal, but it is nice to see everyone make an effort to dress up.
Enjoy your trip!
RCCL Oasis of the Seas 2012, 2013
Carnival Ecstasy 2012
Ruby Princess 2011
Sapphire Princess 2011
Carnival Fascination 2011
Carnival Inspiration 2008
Carnival Spirit 2007, 2009
Carnival Holiday 2007
Carnival Fantasy 2006, 2009, 2010
Costa Mediterranea 2005
Carnival Glory 2003
Carnival Conquest 2003, 2005
RCCL Rhapsody of the Seas 2002
Carnival Destiny 2001
Carnival Paradise 1999, 2000
Carnival Imagination 1997, 2008
Carnival Celebration 1996
Thanks for the replies. My husband always wears a suit on formal nights. Never really paid that much attention to everyone else. Have seen a lot of informal folks on Carnival. We are looking forward to the cruise and warm weather. Today is a bad weather day in Georgia.
2005 Carnival Fantasy
2007 Carnival Sensation
2008 Royal Caribbean Mariner of the Seas
2010 Carnival Dream
2012 Carnival Freedom
2012 Carnival Sensation
2012 Princess Caribbean Princess