How Cruise Ships Got So Big

You may have seen a visual comparison of the Titanic (the biggest ship of its time) with a modern cruise ship to show how enormous cruise ships have become. You also have to understand they are two different kinds of ships, with different purposes, and that's why they are built that way and look nothing alike. In fact, cruise ships were a new idea that sprung up to keep ocean liners earning money in the off season, and grew substantially when people started traveling by plane. Today, cruise ships are pretty much modern resorts in one crowded building that happen to float. But at least you can tell people you've been to the Bahamas without having to drive or find a pit stop on the way. Vox takes us from luxury ocean liners to modern cruise ships and explains why they are so different.