It sounds like an April Fool's joke, but it's for real: A giant new ship on order for Carnival Cruise Line will boast a deck-top roller coaster.

Carnival president Christine Duffy tells USA TODAY the line plans one of the attractions for the 5,200-passenger Carnival Mardi Gras, the first of a new series of giant vessels that will begin arriving in 2020. It'll be the first roller coaster on a cruise ship.

To be called BOLT: Ultimate Sea Coaster, the attraction will be 800 feet long and feature twists, turns and drops with riders reaching speeds of nearly 40 miles per hour.

"It will be a thrill ride," says Duffy, who rode a prototype of the attraction assembled by its manufacturer, Munich-based Maurer Rides. "We think it's a really cool innovation for Mardi Gras, which will have a lot of new guest features and experiences that we have not done before."

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The new attraction will be just the latest in a series of over-the-top amusements to debut on cruise ships in recent years. Two of Norwegian Cruise Line's newest ships, Norwegian Bliss and Norwegian Joy, boast go-cart racing tracks on their top decks. The newest series of Royal Caribbean vessels offer rides into the sky in glass capsules. The most recent series of Disney ships have "water coasters" up top.

Carnival itself offers a first-of-its-kind-at-sea pedaled "sky ride" on its two newest ships, Carnival Horizon and Carnival Vista.

"People always want more, whether it is (for their) vacations or anything else," Duffy says, explaining the trend. "They're looking for something new, different and exciting."



Duffy says BOLT will be an all-electric roller coaster. While not nearly as long or fast as the biggest roller coasters on land, some of which extend thousands of feet and hit speeds over 100 miles per hour, it will feature a track that soars 187 feet above sea level. Riders will ride in vehicles that resemble motorcycles.

The ride will begin with a forward launch where riders can achieve race car-like levels of acceleration and culminate with a hair-pin turn around Mardi Gras' funnel.

In a twist, riders will be able to control their speed. Duffy says they'll be able to slow BOLT's vehicles to savor the views from the top of the attraction.

"We wanted to be able to give guests (the chance to have) that visual from the top of the ship," she says.

Duffy says Carnival's design team has worked closely with the ride's manufacturer and the ship's builder to ensure the attraction will be safe and reliable atop a cruise ship. The vessel is being built by the Meyer Turku shipyard in Turku, Finland. Meyer Turku is one of the only shipyards in the world capable of building a cruise vessel as large as Mardi Gras.

"Certainly it has been tested and studied," Duffy says. "Safety is the No. 1 priority for us."

Duffy notes there may be times when wind or (other) weather causes the ride to close, as is the case with the SkyRide attractions atop Horizon and Vista. But "it's been designed specifically to be a roller coaster at sea."

At 180,000 tons, Mardi Gras will be the sixth-biggest cruise ship in the world at the time it debuts and by far the biggest vessel ever for Carnival. It's named after the first-ever Carnival ship, which sailed for the line from 1972 to 1993.

In a sign of just how much has changed in the cruise industry over the past four decades, the new Carnival ship will be more than six times larger than its namesake.

Carnival already has revealed Mardi Gras will be based in Port Canaveral, Florida. Itineraries won't be announced until January.

Construction on a sister ship to Mardi Gras will begin in 2020. It's expected to be completed in 2022.

Carnival currently operates 26 cruise vessels from more than a dozen ports.