Hong Kong-based cruise line company Dream Cruises will inaugurate the world's longest roller coaster at sea in 2021 with the entry into service of its newest cruise ship, Global Dream.

Over 300 meters (980 feet) in length, the world's longest roller coaster at sea is named "Space Cruiser." This twisting demon will hurl three cars, each with two riders, down the track at speeds in excess of 60 km/h (37 miles per hour).

This top speed is quite tame when compared to the world's fastest roller coaster. This distinction goes to the Formula Rossa roller coaster located at Ferrari World in Abu Dhabi with a top speed of 240 km/h (150 mph).

Space Cruiser will be the central attraction of a huge new theme park on the ship. It will be an interactive driving experience where passengers control the speed of the ride. Dream Cruises say a ride on Space Cruiser is akin to the experience of flying over the sea.

Only one other cruise liner deploys a sea roller coaster: the Mardi Gras, a ship of Carnival Cruise Lines set to sail in 2020. This sea coaster goes by the name of "BOLT: Ultimate Sea Coaster."

Carnival describes BOLT as "a heart-pounding rush of adrenaline offering nearly 800 feet of exhilarating twists, turns and drops with riders reaching speeds of nearly 40 miles per hour." As you can read from the description, BOLT will be a tad faster than Space Cruiser (64 km/h versus 60 km/h). But Space Cruiser will be much longer than BOLT (300 meters versus 240 meters).

Global Dream is currently under construction in Germany and is set to begin commercial cruises in 2021. Construction began in March 2018. The ship's homeport will be Shanghai.

She will weigh 204,000 gross tons, the heaviest and largest among the four cruise ships that are part of the Dream Cruises fleet. Global Dream will ply Asian waters.

Both Space Cruiser and BOLT were designed and are being built by Germany's Maurer AG, one of the world's leading makers of roller coasters.

Space Cruiser, the world's longest sea roller coaster aboard the cruise ship, Global Dream
A car speeds along Space Cruiser, the world's longest sea roller coaster aboard the cruise ship, Global Dream (illustration). Dream Cruises