Before you use your coupon, try this.
Go to http://www.cruisecompete.com and put in a request for the sailing you're interested in. Here, travel agents compete with each other to offer you the best deal.
I think you'll find that the best offer you get here is better than the price you would pay with the coupon. You should probably note that you have a coupon in the comments, but what Carnival usually does is make the coupon apply only to a higher base cruise rate--i.e., you go through the effort of using the coupon only to pay a higher price than a good agent can get you.
Find and share cruises coupon codes and promo codes for great discounts at.Sale. Cruise Direct. Save. 7 Night Mediterranean Cruises From $1,499 on . ?Attractions · ?Carnival · ?Celebrity Cruises Coupons · ?Odyssey Cruises Coupons