Carnival Cruise Lines has a number of cruise options that tour this region of Mexico. Any cruise that makes Cozumel a port of call will have the potential for trips to Cancun. As with most cruises going to this region of Mexico, if you want to find the best deal, you should look for cruises that are departing from Miami. Carnival offers three and four day cruises to the region that leave from Miami, as well as offering departures from Ft. Lauderdale and Orlando. An interior room on a ship leaving from Miami for a three day cruise can cost as little as $149 with Carnival.
Celebrity Cruises also offer a large number of cruises that visit this region of Mexico and the Caribbean. Again, the best deals tend to be had when you book a cruise that departs from Miami. If you book at the right time, a four-night cruise on the Celebrity Century ship can be had for just under $200, which will take you to the Cancun and Cozumel regions.
Princess Cruise lines is another of the major cruise providers that has many regularly scheduled visits to the Cancun and Cozumel areas. They feature a wide selection of shore excursions on their cruises which include events like tours of many of the ancient ruins in the area. On Princess Cruise lines, a 7-day cruise that tours the Caribbean and includes passage through the Cozumel and Cancun regions, including a stop in Cozumel, an interior room can cost you less then $500.