Looking for a way to set sail without having to spend a ton? You’ll want to check out Carnival’s latest flash sale — but you’re going to need to act fast.Carnival Cruise Line, the world’s second-largest cruise line, is slashing prices through Thursday, offering up to 40% off cruise rates during its three-day flash sale. Cruises start at just $109 per person for a four-day sailing.Most cruises included in the sale depart from ports in Florida — Port Canaveral, Miami and Jacksonville — and sail either to the Bahamas or through the Caribbean. However, we found one option for a four-night sailing to Baja Mexico departing from Carnival’s Los Angeles cruise port in Long Beach, California.Note that these prices don’t include taxes, fees and port expenses, which add between $75 and $427 per passenger. Automatic gratuities of $14.50 per person per day also add to the cost of the cruise; they can either be paid at the time of booking or added to your shipboard bill. All pricing is based on double occupancy.Sale fares only apply to windowless inside cabins and ocean-view rooms (which come with a window you can’t open and possibly an obstructed view). The discounted rooms are all guaranteed cabins, meaning the cruise line will pick your specific room location, so you risk ending up in a less desirable cabin within the room type you booked (or, on the flip side, you could wind up with an upgrade).In addition to the current flash sale, Carnival is offering up to $100 in onboard spending credits for holiday sailings.Ready to set sail? Here’s what you need to know.For more cruise news, reviews and tips, sign up for TPG’s cruise newsletter.(Photo courtesy of Carnival Cruise Line)Deal basicsCruise line: Carnival Cruise Line.Departure ports: Sailing from Jacksonville, Port Canaveral (Orlando), Miami and Los Angeles to ports in the Bahamas, Caribbean and Baja Mexico.How to book: Book online directly through the sale link or through a travel professional.Travel dates: Select sailings through January 2023.Book by: Aug. 11, 2022.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Sample dealsIf you can head out of town as early as next week, you can find a great price on a four-night sailing to Baja Mexico, departing from Long Beach (near Los Angeles) on Aug. 15. Fares start at $109 per person per night for a windowless inside room (before taxes, fees and gratuities), and include all meals, shows and entertainment, as well as daily housekeeping.(Screenshot from Carnival)For a prime December deal out of Miami, check out this four-day Western Caribbean sailing on Carnival Conquest. Prices start at $137 per person, based on double occupancy, in an inside cabin for a sailing to Key West, Florida, and Cozumel, Mexico.(Screenshot from Carnival)Bottom lineAct fast to take advantage of this Carnival flash sale and receive up to 40% off cruise prices for travel starting now through January 2023.Planning a cruise? Start with these stories:The 5 most desirable cabin locations on any cruise shipThe 8 worst cabin locations on any cruise shipA quick guide to the most popular cruise lines21 tips and tricks that will make your cruise go smoothly15 ways cruisers waste money12 best cruises for people who never want to grow upWhat to pack for your first cruise