My wife doesn't want to go way back to the early days of cruising when all men wore jackets and ties and even tuxedos.  We're going on the Silver Shadow in a little over a month, and packing all that garb will require us to check bags (which is something we haven't done for years now).  Just how strict are the dress codes?  Can I get away with just a sport coat and tie, or must I bring a dark suit?