Modern cruise ships have an average weight of around 100,000 GRT (gross registered tons). Some of the larger ships are more than double that weight!
Of course, this doesn’t include the weight of thousands of human passengers and everything they’ve brought with them.
Consider the physical size of the average cruise ship too. The largest vessels have a similar number of rooms to mega-resorts like Mandalay Bay in Las Vegas. And if you stood a large cruise ship up vertically, it would be as tall as (or even taller than) New York’s Chrysler Building!
It’s hard to imagine anything as large and heavy as a cruise ship being able to move — much less glide effortlessly through the water. Cruise ships are modern marvels not just for their size and amenities, but also for their (surprisingly fast) travel speed.
Have you ever stood on the deck and wondered, “How fast do cruise ships go?” If so, you’ve come to the right place for answers. Keep reading for our in-depth guide to cruise ship speed.
In This Article…
How Fast Do Cruise Ships Go?
The average cruise ship speed is about 18-22 knots (or 20-25 MPH). Keep in mind that this is the average speed, not the fastest speed the ship can travel. There are also a number of factors that impact travel speed, but we’ll get to that in a moment.
First, let’s briefly discuss two important terms when it comes to cruise ship speed.
Top Speed vs Cruising Speed
Your car can probably reach a top speed of over 100 MPH, but how often do you drive it that fast?
Similarly, most cruise ships are capable of traveling faster than 18-22 knots. But unless there’s a compelling reason to do so (such as avoiding severe weather), they’ll rarely travel at top speed.
Instead, cruise ships generally travel at an optimized cruising speed. This speed is fast enough to make it to the next port of call on time but slow enough to provide a safe, comfortable journey for all aboard.
Cruising speed also improves fuel efficiency, the same way a certain speed improves fuel efficiency for your car. You may be able to drive your car at 80 MPH on the highway, but you’ll burn through a lot less gas if you drive at a steady 65 MPH.
Why is fuel efficiency so important for cruise ships? A large ship can burn through 250 tons of fuel every day. That’s equal to over 80,000 gallons of gasoline — more than you’ll use to fuel your cars in a lifetime!
For this reason, cruise ships strive to find that sweet spot between a swift cruising speed and maximum fuel efficiency.
What’s a Knot Anyway?
Before we go further, let’s answer another common question related to boat travel: the knot. Why do we measure ship speed (and aircraft speed) in knots?
To understand the term, we need to travel back in time to the days of ancient seafaring. Without the modern GPS tools and tracking equipment that we have today, sailors had to find other ways to measure their ship’s speed.
The most common method was known as the “Dutchman’s Log.” Sailors would throw a piece of wood (or another floatable object) overboard. Then they would count how much time passed before the object passed the stern.
By the 17th century, the practice evolved to include a length of rope with knots tied at regular intervals. Sailors would toss the rope into the water and count the number of knots that drifted past the ship’s stern in a given amount of time.
Eventually, one “knot” came to equal one nautical mile per hour. A land mile covers 5,280 feet, while a nautical mile covers 6,076 feet — a difference of 15%.
In other words, one knot is approximately 1.15 miles per hour. This is why 18-22 knots equals about 22-25 MPH.
Although it sounds like a fun science experiment, no one these days has to stand on the bow and toss a knotted rope over the side. Modern cruise ships rely on GPS tools to monitor and adjust speed.
Factors That Affect Cruise Ship Speed
So far, we’ve discussed how fast cruise ships go (on average), as well as how to measure travel speed in knots. Now let’s take a look at four different factors that affect cruise ship traveling speed.
1. The Cruise Itinerary
During your cruise, you’re free to do whatever you like, whenever you like — eat, sleep, swim, and enjoy the amazing amenities.
The ship, however, runs on a very tight schedule. If you’re traveling to five different ports of call in seven days, the captain must ensure you reach each new port at the specified time.
As an example, let’s say you’re cruising from Miami overnight to a private island in the Bahamas. Even though your ship can easily cruise at 22 knots, the island is less than 200 miles away. To reach the island on time in the morning, the ship needs to sail slower than its normal cruising speed.
You’ll also notice the ship travels slower when you’re approaching a new harbor and pulling into the port. If you do happen to arrive early, the ship may even drop anchor off-shore until it’s time to dock. These are common precautions that ensure the safety of everyone on board.
On the other hand, let’s say you’re crossing a huge stretch of ocean on a Transatlantic cruise. For those long days at sea, the ship will likely sail at its maximum cruising speed to cover more miles faster.
2. Weather & Sea Conditions
Ideally, every cruise experience would be nothing but smooth sailing. In the real world, however, ships are at the mercy of Mother Nature.
Thunderstorms and rough seas can appear out of nowhere, especially in tropical locales. Hurricane season can also have an impact on cruise ship speed and travel itineraries. A cruise ship may need to speed up, slow down, or adjust its course to avoid severe weather.
Meanwhile, ships that sail to Antarctica or through Alaska’s Inside Passage may need to adjust their speed if there are glaciers or icebergs in the area.
Wind speed and direction play a major role in cruise ship speed as well. If the ship is sailing into a headwind, it needs to use more fuel and engine power to maintain speed. If there’s a driving tailwind, the captain may choose to reduce the engine power to avoid arriving at the next port too early.
Any decisions to speed up or slow down are always made with everyone’s safety and comfort in mind.
3. Unexpected Emergencies
Although less common than the other factors we discussed, emergencies can and do happen at sea.
A passenger onboard may have a medical emergency and need transportation to the nearest hospital. Or perhaps another ship in the area sends out a distress signal and your cruise ship is the closest vessel that can help.
In either scenario, the ship may speed up or slow down to respond to these emergency situations.
4. Type of Engines
There are three main types of engines used in cruise ships today. They are:
- Aero derivative gas turbine engines
- Diesel-electric engines
- Liquified Natural Gas (LNG) engines
Aero derivative gas turbine engines and diesel-electric engines both rely on super-heated air to combust. They also use massive amounts of fuel.
Usually, the diesel fuel that they use for locomotion is a lower grade than what goes into roadworthy diesel vehicles. The lower efficiency means there’s more polluting exhaust, too.
Aero derivative gas turbine engines turn heat into mechanical energy, which then is transformed by a turbine into electrical energy.
Diesel engines work slightly differently and are known for high torque. Diesel-electric engines turn a shaft that generates electricity instead.
This electricity powers the ship’s systems and propellors. These propellor systems turn “screws” instead of long propellors like a plane. These screws need a lot of torque, instead of a lot of high-speed to operate.
LNG engines are able to increase efficiency by 15% or more, especially with waste heat recovery (WHR) systems in place. LNG stands for liquified natural gas and was first used for tankers and carriers. It’s now breaking into a fuel source for other large vessels.
These LNG engines turn steam engines to generate electricity.
The economic and environmental impact of LNG engines is high. 100% of sulfur compounds and about 85% of nitrogen oxide is negated by using this fuel source.
Since LNG engines reduce emissions and increase efficiency while maintaining cruising speed, what’s not to love?
What’s the Fastest Cruise Ship in History?
In the post-war years of World War II, many ocean liners were competing to cross the Atlantic in the shortest amount of time.
In 1952, the honors went to the SS United States, which still holds the record for the fastest Transatlantic crossing ever.
On its maiden voyage, it maintained a cruising speed of 35.5 knots and reached a top speed of 39 knots. That’s over 40 MPH, which is as fast as a galloping racehorse!
Although the ship has been retired since 1969, there’s talk of reviving this speed demon and bringing it back into active service.
Cruise Ship Speed FAQs
We’re almost at the end of our discussion about cruise ship speed. Let’s round things out with a quick FAQ session to recap what we’ve learned.
In 24 hours, a cruise ship can cover approximately 480 nautical miles or 550 land miles. Examples of this distance include:
Port Canaveral, Florida to Havana, Cuba
Southhampton, England to Newcastle Upon Tyne, England
Barcelona, Spain to Livorno (Pisa), Italy
Of course, these are under ideal circumstances. Depending on the weather and other factors, a ship may take longer to travel 480 nautical miles.
Although it’s no longer the longest or largest cruise ship, the Queen Mary 2 (QM2) is still the fastest cruise ship in service today.
This luxury ocean liner is the jewel of the Cunard Line’s fleet. It holds 1,250 crew members and up to 2,700 passengers. Built in 2003, its average cruising speed is 24-26 knots while its top speed is an impressive 30 knots.
Fun fact: A common joke in the industry is that the QM2 can reverse faster than most other ships can go forward.
Outside of initial testing before they’re commissioned into service, most cruise ships will never travel at their top speed. This is because of:
Itineraries and schedules
Weather and sea conditions
Fuel performance and efficiency
Emergencies at sea
Safety precautions during docking
Distance from shore or other vessels
For these reasons, cruise ships mostly operate at a standard cruising speed that strikes a balance between safety and efficiency.
As big “floating cities,” cruise ships require a lot of resources to travel and operate. What are the major cruise companies doing to make their ships more eco-friendly? Here are some trends towards greener tourism for cruise ships:
Changes in power sources (i.e, LNG engines)
Alternative fuel sources
Reducing or eliminating single-use plastic products
Improving food use and waste management
Advanced technologies to reduce drag and recycle wastewater