The biggest cruise ship ever built is about to touch water for the first time

The biggest cruise ship ever built will hit a major construction milestone this weekend.

Royal Caribbean's Wonder of the Seas will touch water for the first time as it's "floated out" from a dry dock at the Chantiers de l'Atlantique shipyard in St. Nazaire, France, where it has been under construction for more than a year.

The 18-deck-high vessel -- the latest in the line's giant Oasis Class of ships -- will transfer to a "wet dock" where finishing work will continue into next year.

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Wonder of the Seas had been scheduled to debut in 2021, but Royal Caribbean recently said the vessel's debut would be pushed back by around 10 months, citing the coronavirus pandemic. That would push its arrival into 2022.

The early stages of the construction of a cruise ship take place in a dry dock facility. Once the exterior of a vessel is complete, the dry dock is flooded and the ship is floated to a wet dock facility where construction continues. It's considered a significant turning point in the building of a vessel.

It may seem odd that cruise lines are continuing to build new ships even as most of their existing ships aren't sailing due to the coronavirus crisis. But cruise companies expect the cruise industry to resume growing at a significant pace once the crisis has passed, resulting in demand for additional vessels.

Related: The ultimate guide to Royal Caribbean ships and itineraries

While lines have been permanently retiring some older ships in recent months in anticipation of a slow restart to cruising, the leaders of the biggest cruise companies have said they have no plans to cancel orders for new ships. They've said they would rather keep the new ships and eliminate older ships if they need to cut capacity in the short term.

The float out of Wonder of the Seas is scheduled to take place around 7 a.m. on Saturday, Sept. 5, according to French media outlet Ouest France.

Wonder of the Seas will be the fifth vessel in Royal Caribbean’s groundbreaking Oasis Class series of ships, which are more than 20% bigger than any other cruise ships afloat.

The four existing Oasis Class vessels include the 228,081-ton Symphony of the Seas — the current size leader in the cruise world. Eighteen decks high and nearly 1,200 feet long, it can hold up to 6,680 passengers at maximum occupancy.

The vessel and its sisters resemble megaresorts on land with dozens of restaurants and bars, Broadway-style entertainment, casinos and lots of deck-top attractions. Symphony of the Seas has three pool areas, giant waterslides, rock climbing walls, surfing simulators, a miniature golf course and even an ice skating rink.

Related: How to book a cruise with points and miles

While Royal Caribbean has been coy as to just how big Wonder of the Seas will be, a top executive at Royal Caribbean hinted to The Points Guy last year that the newcomer (and another Oasis Class ship on order for 2023) are likely to set new size records.

“It’s certainly a moniker that Royal Caribbean owns,” Royal Caribbean’s vice president for product development, Laura Hodges-Bethge, told TPG. “When you look at Symphony, it was, I don’t know, a couple metric tons [bigger than its predecessor]?” For these new ships, she said, “I can’t imagine that wouldn’t be the same thing.”

Every Oasis Class ship that has rolled out has been a little bigger than the last.

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