The Queen Mary hotel and tourist attraction in California Wallpaper101/Getty Images
Before the advent of jets like the de Havilland Comet and Boeing's iconic 707 in the 1950s, overseas travel was accomplished almost exclusively by ship. These simple Point A to Point B journeys — such as New York City to Southampton, England — are known as "line voyages." Hence, the vessels involved were called ocean liners. Nowadays, the titles ocean liner and cruise ship are often used interchangeably to describe large ships, but the differences between them are actually significant.
While ocean liners were primarily looked upon as transportation between continents, some amenities likes game rooms and live bands were present to keep passengers entertained during the lengthy sea crossings. That said, outdoor activities were sparse. In nice weather, a nap in a deck chair or a game of shuffleboard might be possible. But especially on the North Atlantic route between the United States and Europe, the weather was often blustery.
Just as the passenger spaces were designed for challenging wind and waves, so were the ships' hulls. Ocean liners feature deep drafts, measured as the depth of the hull below the waterline, to improve handling in rough conditions. Additionally, the hull is fashioned from thicker steel to stand up to the repeated abuse of pounding waves and the high speeds necessary to maintain schedules.
It's all about speed
The ocean liner SS United States rusting at dock in Philadelphia. Brian E Kushner/Shutterstock
During the era of ocean liners, speed was a serious bragging right between the national carriers of different countries. A prestigious award called the Blue Riband was bestowed upon the ship with the fastest average speed while crossing the Atlantic. In 1936, an elaborate award statue called the Hales Trophy was introduced as an additional prize for the ship holding the Blue Riband speed record.
For decades, Britain, France, Germany, and Italy traded the Blue Riband back and forth as ever-faster and more modern ocean liners emerged. In 1952, U.S. Lines won the Blue Riband with its eponymous superliner the SS United States. This 240,000-horsepower juggernaut blasted from New York to Southampton in just three days, 10 hours, and 40 minutes at an average speed of over 35 knots (over 40 mph). That crossing — a record that still stands today — shaved a full 10 hours off the previous record held by Cunard's Queen Mary, which now serves a static tourist attraction in Long Beach, California. The SS United States wasn't as lucky as Queen Mary in retirement and is expected to be sunk as the world's largest artificial reef off the Florida coast in late 2025 or early 2026.
By contrast, cruise ships are much slower. According to cruise giant Royal Caribbean, the average cruise ship operating speed is just 18 to 20 knots (about 20 to 23 mph). That's because a cruise is meant to be savored instead of being utilitarian transportation between continents. Lounging by the pool with an umbrella drink on a windswept deck at 40 mph doesn't sound very enjoyable.
The rise of cruise ships
MSC Seascape cruise ship at sea Deutschlandreform/Shutterstock
While moving at 40 mph on a 990-foot-long ship is doubtlessly impressive, even the fastest ocean liners were no match for jets, which could cover the North Atlantic in hours rather than days. At the same time that jets were putting ocean liners out of business, a fledging cruise industry started to develop. Ironically, many of the early cruise ships were actually retired ocean liners converted for cruising between different ports of call on a leisurely journey.
For example, the French Line's gigantic ocean liner the SS France and its distinctive winged funnels became the much-loved cruise ship the SS Norway after purchase by Norwegian Cruise Lines in 1979. This conversion involved adding additional cabins with balconies, two outdoor swimming pools, and an open-air buffet dining space. Norwegian also removed two of the ship's four propellers, which weren't necessary for low-speed cruising — a move that improved fuel consumption.
Nowadays, newly built cruise ships have little traditional nautical flair. Instead, most look like someone turned an apartment building on its side. Some cruise ships do make occasional (and slow) transatlantic crossings in the course of repositioning to a new seasonal port, but meandering slowly between ports — frequently beginning and ending in the same place — is the order of the day. Modern cruise ships have rock climbing walls, go-cart tracks, replicas of Old West train cars, and all manner of gimmicks that make the ship a destination in itself.
As cruises have replaced ocean liners, there's only one true liner remaining — Cunard's Queen Mary 2, launched in 2004. However, it only does transatlantic crossings part of the year and is equipped to double as a cruise ship when necessary.