What drinks can you get without a drink card on the Carnival cruise lines?

I’m going on a cruise in August on Carnival Sensation and am considering whether or not to buy a drink card. What drinks are offered by the cruise without a drink card?

How much are drinks on carnival cruise line?

My boyfriend and I are going on our first cruise in Oct. 09. We will be on the Carnival Imagination. We are curious about the average cost of drinks. We know that the tips are added.