Leaving from Galveston Dec 8 on Carnival Celebration...do I really need 'cocktail' type evening wear? Have plenty of silk pants/shirts/skirts combos, but all publicity pics always have women in spaghetti strap type after 5 dresses. Mine are not quiet that dressy, besides I heard it gets cool on board in the evening. Is it really that dressy at night? Have friend that says this cruise is a little more casual than others...any response? Thanks!!!!