I think smart casual means anything other than cutoffs or clothing like that. On the Radiance in March smart casual was more on the casual than the smart side.(Although I don't really know how smart should look. (
People looked very nice, but also very comfortable. Some wore shorts, some skirts, slacks.....I didn't see a lot of men in ties and sportcoats on those nights........ Mistly slacks and nice shirts, lots of polo type..... Hope that helps.