In 1970, about 500,000 people went on cruises. In 2013, that number was higher than 20 million.

“It introduced cruising to a nontraditional cruise audience — which was, at the time, made of up the clichéd ‘newlywed and nearly dead,’” Carolyn Spencer Brown, editor in chief of Cruise Critic, told CNBC. “The show made cruising sexy again and brought new life to the industry. It was fun, exotic and glamorous.”

The success of The Love Boat was a surprise even to those who were in it.

“When we first went on the air, almost every critic but one said we’re gonna sink like the Titanic,” Gavin MacLeod, who played Captain Stubing, told Mashable.

“But it gave people something to dream about.”

The origins of cruising

Why did people board giant ships in the 19th century? To get to the other side of the ocean, of course.

Ocean liners were not designed to be comfortable, either, and engineering primarily focused on going long distances. There were few amenities on board, and that made them somewhat unappealing to people looking for a vacation.

The first “cruise ship” was built in 1900 by a German shipping magnate that wanted to appeal to wealthy travelers with the means to float around the ocean for a while — for fun. It was called the Prinzessin Victoria Luise, boasting 120 first-class cabins, a library and a gym, and was designed to mimic the look of a yacht.

The Prinzessin Victoria Luise was the first ship built for the purpose of cruising. It was in operation from 1900 to 1906.

The Prinzessin only made it six years before it was accidentally grounded in Jamaica, but luxury cruise ships were only getting started.

After World War II, ships were the de facto way to cross the Atlantic, and they got nicer — bigger rooms, expensive mattresses, expensive food options — making it more comfortable and fashionable to spend weeks aboard. But by the 1970s, traveling long distances on ships became unnecessary, thanks to the rise of modern aviation.

The Loooooovvvvveee Boooooooooaaaattt

When Ted Lange’s agent told him he should play the part of a bartender on a new television series set on a cruise ship, he thought it sounded boring. And that the part, which was minimal in the beginning, wasn’t worth it.

But his agent sold it to him as a chance to relax.

“My agent says, ‘Have you ever been on a cruise? Well, think of it as a vacation. You’ll get a chance to see Mexico,’” Lange told Mashable. “And it was fantastic.”

From left: Fred Grandy (Gopher), Ted Lange (Isaac the bartender), Gavin MacLeod (Captain Stubing), Lauren Tewes (Julie), and Bernie Kopell (Doc).

MacLeod was also reticent when first approached by Aaron Spelling about the show. He had just finished a long run on The Mary Tyler Moore Show as Murray Slaughter and thought he would “never, never, never” do another series. But Spelling sought him out specifically to play the Captain.

“It was like Murray got a promotion,” MacLeod told Mashable. “The script was so interesting. The Love Boat was just something new and different.”

And it was new in its format: It was an hour-long comedic show when the standard was 30 minutes, and each episode had three intermingling (and sometimes confusing) story lines.

Both MacLeod and Lange were with the show since its pilot in 1977, but that was actually the third pilot (the first two had been rejected). Sometimes, the third time really is the charm.

The weekly show affected Princess Cruises in a few unexpected ways.

Lange had a mustache when he started filming the show; the English bartenders on the ship said that didn’t work because he was supposed to be working in food services.

“Well, if I shave off this mustache, I’ll look like I’m 17,” Lange recalls thinking. So he kept it, and two years later saw the bartenders growing mustaches to match the passengers’ perception of cruise employees (and to get more tips).

MacLeod says that the presence of kids and families on the show meant the cruise lines had to think about activities for kids.

At the christening of the new Regal Princess on Wednesday, all six original cast members became godparents to the ship. For the occasion, Princess also brought in many of the other cast members and guest stars — like Marion Ross, Charo and Florence Henderson — who appeared on the show over the years.

The original cast of the Love Boat reunited on Nov. 5, 2014, to christen Princess Cruises’ new boat the Regal Princess.

The company has gotten the crew back together a few times over the years, and MacLeod has served as spokesman since the show ended in 1986.

Cruising into the future

As MacLeod pointed out, cruising is growing in popularity every year. The rate at which onboard amenities have changed has only sped up since The Love Boat went off the air in 1986.

The show’s Pacific Princess carried 640 people with a single dining hall. The Regal Princess carries more than 3,600, has 10 restaurants, and includes on-board amenities like an over-water SeaWalk, a top-deck glass-bottomed walkway extending 28 feet beyond the edge of the ship.

Princess Cruises serves about 1.7 million passengers annually in an industry that saw 20 million passengers in 2013. Cruising provides more than 300,000 jobs and generating more than $35 billion in revenue in the U.S., according to the American Association of Port Authorities.

“We’ve sailed to over 100 countries, and have for many years, but we are growing quite significantly,” said Schwartz, the Princess Cruises president, adding that she thinks it’s amazing that 50 years into the business Princess is still changing. “We’re designing itineraries to explore Japan and Korea and Russia that have literally never been done before.”

The other big cruise lines, including Carnival Cruise Lines, Celebrity Cruises, Costa Cruises, Holland America Line, Norwegian Cruise Line and Royal Caribbean International, are also growing, looking to Asia as an opportunity for expansion.

“It’s very humbling for all of us to think, as actors, who got a job that turned out to be almost a lifetime job,” says MacLeod.

“We certainly created an industry.”

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