Cruise Ships Series: Explainer on the Largest Classes of Colossal Cruise Ships

Fast-forward to 2021, almost all the cruise ships today are of colossal scale and are at least three times larger than the Titanic.

The Symphony of the Seas, the largest cruise ship today in 2021, is five times the size and tonnage of the Titanic. The Symphony of the Seas is a 228,081-tonne behemoth, compared to the 40,000 tonne Titanic.

Length-wise, the Symphony of the Seas is 362 meters long, compared to the Titanic which is 269.1 meters long. The Titanic can accommodate 2,435 passengers with a 892-strong crew while the Symphony can hold a whopping 6,680 passengers and a 2,200-strong crew. Check out the head-to-head comparison page above to compare between these two iconic cruise ships.

These are the five largest classes of cruise ships in the world (as of 2021). The largest cruise ships are the Oasis-class cruise ships of Royal Caribbean International.

Royal Caribbean's Oasis-class cruise ships are the largest class of cruise ships in the world. With a maximum beam of 61-66 meters and an overall length of 361-362 meters, the Oasis cruise ships - Oasis of the Seas, allure of the Seas, Harmony of the seas, Symphony of the Seas and the upcoming Wonder of the Seas - are the benemoths of the cruise waters. Each of these cruise ships can carry over 5,400 passengers within its 2,700 rooms spread across 18 decks.

With a gross tonnage of 225,000 to 228,000 GT, Oasis-class ships are powered by six medium-speed, marine-diesel generating sets, comprised of three 16-cylinder Wärtsilä 16V46D common rail engines producing 18,480 kilowatts (24,780 hp) each and three similar 12-cylinder Wärtsilä 12V46D engines producing 13,860 kilowatts (18,590 hp) each.

The Excellence class is the second largest class of cruise ships in the industry today. The current Excellence-class cruise ships are owned by Costa Cruises (Costa Smeralda), P&O Cruises (MS Iona) and AIDA Cruises (AIDANova), which are subsidiaries of the Carnival Corporation & PLC.

Excellence-class cruise ships clock in around the gross tonnage of 183,000 to 185,000 GT and spans 337 meters to 344 meters in overall length. Each of these cruise ships can carry over 5,200 passengers.

The Meraviglia class of cruises is the third largest class of cruise ships and the largest class of cruise ships owned by MSC Cruises. Meraviglia-class cruise ships include MSC Grandiosa (Meraviglia Plus), MSC Meraviglia and MSC Bellissima.

The Meraviglia-class cruise ships have a gross tonnage of between 171,000 and 181,000 GT (Meraviglia Plus) and stretches between 315 meters to 331 meters (Meraviglia Plus). With a height above waterline of 65 meters, these cruise ships come with 18-19 deck floors and can accommodate 4,400 to 4,800 (Mergaviglia Plus) passengers.

The Quantum class is a class of cruise ships from Royal Caribbean International. The 5 completed Quantum-class cruise ships are Spectrum of the Seas, Odyssey of the Seas, Ovation of the Seas, Anthem of the Seas and Quantum of the Seas. Both the Spectrum of the Seas and Odyssey of the Seas are of the slightly larger Quantum Ultra subclass.

The Quantum-class ship's gross tonnage is around 168,000 to 169,000 GT, with an overall length of around 347 meters. Quantum Ultra cruise ships can accommodate up to 4,200 passengers while regular Quantum class ships can hold up to 4,100 passengers.

The Breakaway class is a class of cruise ships from Norwegian Cruise Line, with the Breakaway Plus being a slightly larger subclass. Among the 6 completed Breakaway cruise ships, the Breakaway Plus cruise ships are Norwegian Encore, Norwegian Bliss, Norwegian Joy and Norwegian Escape, while regular Breakaway-class cruise ships are Norwegian Breakaway and Norwegian Getaway.

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