A Rogue Wave Sent a Cruise Ship Flying. Should Cruisers Be Worried?

According to cruisers on board the ship, the incident lasted only about 30 seconds, though the ship continued to rock for hours later. Immediately after the impact, passengers were ordered to return to their cabins while all crew were accounted for. One passenger shared on a cruising website that “Captain Frank said that we encountered an unforeseen squall and were hit by hurricane force 80 mph winds while going 23 knots.”

Impacts on board were immediate and severe, as the sudden tilt caused unsecured items to become airborne, injuring one passenger critically enough to require an unplanned stop in Las Palmas, Spain, for a medical evacuation. A TikTok video showed an electronic advertising screen crashing against someone walking, and one reel posted to Instagram captioned “chaos at sea” shows the mess on board the ship’s duty-free shopping area. In the video, you can see wrecked displays of watches and jewelry, entire wracks of clothing and gift items knocked into walls, and staff trying to move tables as they work around the disarray.

 

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Following the incident, Royal Caribbean issued a statement to media blaming the incident on “sudden wind gusts” (which can cause unexpected waves) and describing the ordeal as “unexpected movement.” The ship eventually continued its course to Miami without further incident.

A ship like Explorer of the Seas — with a length of 1,020 feet, a max width of 157.5 feet, and a weight of approximately 138,194 tons — would need to encounter extraordinarily large waves to cause the reported 45-degree tilt. The extent of the impact of a large wave depends on several factors, including the ship’s center of gravity, ship design, the size of the wave, and the speed and direction with which the save hits the ship. Cruise ships typically have a high center of gravity (due to multiple decks), making them more susceptible to noticeable tilting in severe sea conditions.

Based on general shipbuilding and wave stability calculations, it’s estimated that the Explorer of the Seas would have had to encounter a wave height at least 50 feet tall to cause a 45-degree tilt, particularly if the wave hit the ship’s side. However, it’s possible it could have been a smaller wave that hit the ship when it was already leaning to one direction in the normal course of sailing, which could cause a more dramatic tilt.

Cruise ships bows are designed to smoothly cut through even the largest of waves and swells. Photo: James Steidl/Shutterstock

In short, yes. Cruise ships are designed to travel safely through some of the most remote corners of the ocean and are built to withstand extremes. Although the incident aboard the Explorer of the Seas was likely frightening for passengers and crew, the ship did exactly what it was built to do: it was hit by a wave, listed to one side as predicted, then righted itself and resumed an upright position.

Cruise ships are usually built with deep bows and a hull designed to cut through water and deflect waves to the sides — it’s why cruise ships often can’t enter smaller harbors, as they’re much deeper below the surface than a flat-bottomed boat. But this deep bow also keeps water from splashing on the decks, helping to deflect the immense pressure of waves without stressing the ship. If you’ve ever heard a ship or boat captain mention sailing into waves (rather than parallel to them), that’s part of the reason why.

Cruise ships also usually have stabilizers that extend from the hull to counteract rocking caused by waves, and use ballast systems (tanks that can be filled to lower the ship’s center of gravity) to add more stability in choppy water. Many cruise ships have a dozen or more levels of decks, which is why they also have features designed to counteract the engineering downsides that can cause. Think of cruise ships in large waves like airplanes during extreme turbulence: they can withstand much more than you’d think.

Rogue waves have hit cruise ships occasionally. But because cruise ships can withstand such significant waves, it’s possible that sometimes, passengers don’t even notice. However, there have been a few notable incidents.

In November 2022, a rogue wave hit the Viking Polaris ship during its return to Ushuaia, Argentina, after a cruise to Antartica. The force of the wave caused damage to the ship’s windows and interior spaces, as well as the death of one passenger (killed by shattered glass), and injuries to several more. In 2005, the Norwegian Dawn encountered an estimated 70-foot-tall rogue wave off the coast of Georgia, smashing windows and flooding cabins, and causing a few injuries. The ship sustained structural damage and returned to New York. And in 2023, Hurtigruten’s MS Maud was struck by a rogue wave during a northern lights cruise. It caused a power outage and disabled the ship’s navigation systems, but no injuries were reported.

An ocean monitoring buoy in Thailand. Photo: The Mariner 4291</a/Shutterstock

Rogue waves are a rare but increasingly documented phenomena in oceanography. Once thought to be a myth perpetrated by sailors and captains trying to hide their nautical mistakes, the towering walls of water are very much real, and perhaps more frequent than once thought. A “rogue wave” is defined as a wave at least twice the height of surrounding waves. If it doesn’t meet that criteria, it’s considered an “unexpected wave.” So while all rogue waves are unexpected, not all unexpected waves are rogue waves (though the terms are often used interchangeably as their effects can be similar).

Better and higher-tech monitoring efforts like ocean sensors, satellite observation tools, ship-based radar, and a whole host of AI and data-based monitoring tools have made it much easier for scientists to learn when rogue or unexpected waves occur. So their frequency likely hasn’t increased, but scientists’ ability to track and study them has gotten better.

Photo: ZHMURCHAK/Shutterstock

Rogue and unexpected waves are still rare, and are the result of several natural forces aligning. Scientists think the most likely scenario for a rogue wave to form is “constructive interference,” where smaller waves combine at just the right time to create a much larger wave. This can happen when strong ocean currents meet opposing winds, forcing waves to build up quickly. Based on the captain’s announcement on board, this may have been what happened with the Explorer of the Seas. It’s also why unexpected waves are more common during storms, when strong winds and strong ocean swells are more likely.

However, scientists don’t totally understand what drives rogue waves, and since they usually occur in the middle of the ocean for only a few seconds at a time, they’re quite difficult to study.

Photo: Zivica Kerkez/Shutterstock

While rogue waves are dramatic, they’re still rare, and modern cruise ships are designed to handle rough seas and sudden wave impacts. Given the vast number of cruises that take place each year (31.7 million people cruised in 2023), the fact that any one incident makes global headlines tells you how rare they are. In addition to being built to withstand extreme conditions (sometimes due to their massive size),  cruise ship technology is extremely high tech, and individual ships monitor weather and ocean conditions and set routes that intentionally avoid rougher patches of sea.

It’s been well over 100 years since any large passenger ship was lost at sea — and even then, the ship was only a fraction of the size of today’s smallest ships. In July 1909, the SS Waratah (a passenger and cargo steamship), vanished without a trace between Durban and Cape Town, South Africa. No wreckage or survivors were ever found, and it remains a maritime mystery. Some have theorized that a rogue wave or extremely rough sea was the cause, but without any evidence, it’s likely we’ll never know. However, the SS Waratah was only 500 feet long — large for the time, but even the smallest ship in the Royal Caribbean fleet is nearly twice as long: the 916-foot-long “Grandeur of the Seas.”