Lee Wachtstetter has been living on a cruise ship full-time since she turned 77. Better known as Mama Lee, the 89-year-old Wachtstetter has written a book about her experiences as a permanent cruise ship resident. In I May Be Homeless, But You Should See My Yacht, she explains that she was stuck in a big, empty house after her husband passed away. Instead of moving to a smaller home or assisted living facility, Wachtstetter decided to sell the house and start cruising full-time. She had been on 89 cruises with her husband when he was alive and loved the lifestyle.

"I was in good health. I could afford it. I was already traveling 11 months of the year, and now I no longer had a big house to worry about," wrote Wachtstetter in her book.

Living on a cruise ship provides Wachtstetter with constant companionship, maid services, gourmet meals, access to 24/7 health care, and entertainment. She's visited more than 100 countries and still dances every night on the ship.

"The day before my husband died of cancer in 1997, he told me, 'Don't stop cruising.' So here I am today living a stress-free, fairy-tale life," Wachtstetter told USA Today. And she's not the only one. Wachtstetter is part of a growing trend: Senior citizens are ditching retirement homes for luxury cruise ships in their golden years.

It's hard to find exact figures for how many senior citizens have become permanent cruise ship residents after ditching life on land. It's estimated that cruise ships had 25.3 million passengers in 2017 and about half were between the ages of 50 and 74. A survey from 2018 found that baby boomers and seniors were the most active cruise ship travelers. However, the cruise ship industry doesn't track those who live on board full-time vs. occasional travelers.

Still, cruise ships are responding to this trend. For instance, Oceania Cruises created a Snowbirds in Residence program to let seniors live on board for 58 or 72 days, so they can flee the cold without settling in Florida. Some cruise ships are even creating permanent residency cabins for eager retirees. Considered one of the largest private residential ships, The World provides 165 permanent residences ranging in size from studios to three bedrooms. Another example is the Utopia, which is a planned luxury ship that will offer 190 full-time residences on board ranging in size from 1,439- to 6,500-square-feet. With floor plans that include walk-in closets, multiple bathrooms, private kitchens, and living rooms, these residences will look more like houses than ship cabins. For those who can't afford the residences, Utopia will have a floating hotel with suites on the same ship.

So why are seniors flocking to luxury cruise ships? First, you have to follow the money. Compared to an assisted living facility or nursing home, cruise ships may cost about the same or, in some cases, even less. CNBC reports that a day on Princess Cruises costs about $135. A day in a private room of a nursing home costs $253. When you compare the monthly costs, Princess Cruises adds up to about $4,200, and the private room at the nursing home is nearly $8,000. On the other hand, assisted living facilities cost $119 per day, just a bit less than the cruise ship.

Beyond the potential cost savings, there are the amenities of a cruise ship to consider. Today's ships provide pools, fitness centers, lounge areas, and hot tubs. They offer fine dining, classes, entertainment, housekeeping, and other services. So in addition to being able to travel around the world and see exotic locations, retirees who choose this lifestyle can be pampered on a daily basis. It's no wonder a study from the Journal of the American Geriatrics Society noted that elderly people who lived on a ship had a higher quality of life.

One other big reason for this shift may be health-care access. The paper points out that most assisted living facilities don't have doctors available 24/7. But cruise ships have health facilities with doctors and nurses who live on board. They're capable of handling many medical emergencies. Although a cruise ship wouldn't be an ideal place for someone with severe or chronic health problems, it can work well for many healthy seniors.

For those who love to travel and enjoy the amenities, luxury cruise ships are an attractive alternative retirement option. As Wachtstetter told CBS News: "I don't have to clean house. I don't have to shop, I don't have to cook, I don't have to do anything. I do what I want, when I want, if I want."