For most of us, cruise ships represent a tropical getaway that lasts a week or two. But what about staying on a ship for the rest of your life?

Some retirees pull up anchor and opt for life at sea. A poll from CruiseCritic.com shows that at least a third of respondents said that cruising indefinitely would be the ideal way to spend retirement, while another third said they would consider it if the price were right. According to Cruise Lines International Association, at least half of cruisers are older than 50 — one-quarter are age 60 to 74, and another quarter are 50 to 59.

Crystal Cruises is ahead of the trend. The company recently launched Residences at Sea, a collection of 48 suites located on the top deck of three ships, all of which will open their doors by 2018. Some of these floating apartments are far bigger than many houses — stretching to 4,000 square feet.

It is difficult to argue with a life where all your amenities — Broadway shows, casinos, pools and Jacuzzis, and restaurants — are just a deck away. And think of the tropical vistas, European ports and Alaskan mountain ranges — all views that arguably are more appealing than your backyard.

More than 10 years ago, the Journal of the American Geriatrics Society concluded that, indeed, cruising provides “a better quality of life and is cost-effective for elderly people who need help to live independently.”

Financially speaking, that conclusion still holds true. A per-day stay on the Princess Cruises line averages $135 with long-term care and senior discounts. That’s almost $100 less than the average daily cost of a private room in a nursing home ($229) and comparable to the $119 daily rate in an assisted living facility, according to LongTermCare.gov. Independent living facilities range from about $1,500 to $3,500 a month.

Besides affordability and amenities, another benefit is that cruisers who opt for life at sea get to know the crew on a more intimate level. They become family — unlike what one typically encounters at nursing homes and long-term care facilities, where staff turnover is high and interaction can be impersonal. The longer cruisers stay aboard, the more likely they can earn discounts or receive personalized treatment that typical vacationers don’t get.

The most obvious drawback is health. While most ships include medical centers, long-term care is not yet a reality, especially for people who require around-the-clock monitoring or procedures that go far beyond what ships can handle. Some cruisers might also have issues with property and other assets they own back home.

And here’s another concern: Because of a 1920 law known as the Death on the High Seas Act, the cruise industry enjoys broad immunity from damages in wrongful-death cases involving retirees and other passengers who have no financial dependents. That might or might not worry you, but if considering longterm cruising, you should at least educate yourself about the law.

Finally, homesickness can be a real issue, especially for older people who are at a point in their life when they want to spend time with children, grandchildren and even great-grandchildren. Social media interaction helps, but when you’re midway through an around-the-world cruise, it may not be enough. As any sailor knows, life at sea can be a lonely one, even with around-the-clock shuffleboard.