Book a Carnival Cruise now and get a shipboard credit of up to $500 per cabin to spend on things like shore excursions, spa treatments, drinks by the pool and wine with dinner.

For selected sailings booked by 11:59 p.m. tomorrow, November 30, 2012, Carnival is offering a shipboard credit on top of most of their already low rates.

In addition, past Carnival cruise guests qualify for cabin upgrades. The sale is good for travel on select sailings between now and the end of December, 2013. With the sale, three-to-five-day sailings start at just $329 per person and six-night and longer cruises start at $549.

All of these fares are based on two people sharing a cabin and include accommodations on the ship, and all meals and entertainment on board. Airfare, port taxes and air taxes are additional. To take advantage of this cruise deal, visit the Carnival Cruises Web site, your favorite travel booking site or your travel agent. Use promotion code OCB.