I am also a vegetarian and was thrilled that the Sensation had a vegetarian appetizer and entree available for every meal in the dining room. While I did not see any vegan options, there were plenty of ovo-lacto vegetarian dishes. The beffet eatery on the Lido deck offered many veggie options, too. There was a salad bar and 24 hour cheese pizza available. I am sure that if you are a strict vegan you could call the 1-800 number for Carnival and they could offer assistance. I know that they do not offer kosher meals, but maybe they could assist you with vegan dishes if you let them know your restrictions ahead of time.