If there's one thing retirees love to do, it's travel. Nearly half of baby boomers plan to travel both domestically and internationally, and they'll take, on average, four or five trips each year, according to AARP's 2019 Travel Trends Survey. These trips can be expensive, though. According to the survey, boomers spend an average of $6,600 per year on leisure travel.

While traveling the world is certainly a fun way to spend retirement, not all retirees can afford to do so. In fact, a third of boomers have less than $25,000 saved for retirement, according to a survey from Northwestern Mutual.

Cruise ship at sea

Image source: Getty Images.

That's why some retirees are choosing to take a creative approach to retirement to save money and at the same time live out their dream of traveling the world -- by living on a cruise ship.

It's an unorthodox approach, and it may seem more expensive to live on a cruise ship than to stay at home. But you may be surprised at how affordable cruise ship living can be. That said, it's not the right option for everyone, so it's important to weigh the pros and cons before making any big decisions.

Pros: An adventurous way of life

Cruise prices fluctuate wildly based on the time of year, the destination, and what type of room you're booking. But it's possible to find rooms for less than $100 per day per person. If you're living on a cruise ship full-time, $3,000 per month can seem expensive. Keep in mind, though, that you'll also be saving money in other areas.

For example, most food and drinks are included in your cruise fare. So unless you're splurging on specialty drinks or fancy restaurants, you won't need to budget much for food. You also won't need to worry about other costs you're used to paying at home, such as gas and other commuting costs. If you dive into the cruise living lifestyle headfirst and sell your home and car, you won't even have a mortgage or car payments to take care of. Even if you still want to have a primary address, you can downsize your home just for a place to crash between cruises (and even rent it out while you're away at sea). As a bonus, the extra money you'd save by selling or downsizing and/or renting it out can go toward your retirement fund.

The biggest benefit, though, is essentially treating your retirement like one long vacation. While retirement is already a permanent vacation of sorts, with cruise ship living, you no longer need to worry about housecleaning, yard work, or other chores that you'd still be stuck with at home. And as you age and those things become more difficult, spending the majority of your time on a cruise ship is likely more appealing than moving into an assisted living facility.

Cons: A potentially expensive retirement lifestyle

Although cruise ship living has its financial perks, that doesn't mean it's always more cost effective than retiring on dry land.

One of the biggest considerations you'll need to make involves healthcare. Medicare doesn't cover healthcare expenses outside the U.S., although there are some exceptions if you need medical care aboard a ship. For example, you may be covered by Medicare if you incur medically necessary expenses while in territorial waters adjacent to the U.S. However, if you're more than six hours away from the nearest U.S. port, Medicare won't cover you.

You do have other options, such as a Medigap Plan or travel insurance, but it's important to do your research and talk to an insurance provider to make sure you're choosing the right plan for your situation. If you go without insurance, you could face some hefty medical bills in the event of an illness or accident. This is especially important as you age, because although they may be more affordable than nursing homes or assisted living facilities, cruise ships aren't equipped to provide specialized care.

You'll also need to iron out a few legal and financial details before you go, such as where your Social Security checks should be sent and how you'll handle your taxes, which will likely require the help of a financial planner. Plus, retiring at sea requires a lot of careful planning. You very likely won't find a cruise that will let you live on board 365 days a year, so you'll instead need to book many shorter-term cruises back-to-back. Expect to spend a lot of time researching the best deals and finding cruises that align with your schedule, then double-checking that all the dates line up -- the last thing you want is to mix up your arrival or departure days and end up stranded in a foreign country.

Retiring at sea isn't for everyone, but for the adventure seeker who is looking for an out-of-the-box retirement, it just may be the ideal way to live. Just make sure you do your research ahead of time and plan accordingly so that you can enjoy your retirement to the fullest.