More than 20 million people climb aboard cruise ships each year, according to Trip Savvy. Whether on the open sea or a winding river, cruise vacations stand out as a stellar vacation choice for active adults. On a cruise ship, active adults can experience their ideal vacation, whether they desire leisure time basking in the sun or they crave adventure at excursion sites.

The hardest part of planning a cruise isn’t deciding what to pack—it’s selecting the best cruise line. When researching cruises, active adults can follow the guide below to ensure smooth sailing.

Decide on a Destination

Before making any other vacation decisions, active adults should first contemplate where they would like to visit. While Caribbean cruises have long been the most popular choice, options abound for cruise travelers. Active adults can see breathtaking sights on an Alaskan cruise or explore faraway lands on a European cruise. In fact, some of the most popular cruises today, especially for retirees, are river cruises, which mostly travel through Europe.

Some of the most popular cruise destinations include Glacier Bay, Alaska; Arles, France; and Quebec City, Canada.

Choose When to Travel

River cruises through Europe are the current preference for active adults.

When active adults pick a destination, the next decision is when to go on a cruise. Many retirees have the luxury of traveling whenever they like, opening up many opportunities for an affordable cruise vacation. Consider when other travelers might visit the desired destination and aim to travel during offseasons to get the best deal. For example, an Alaskan cruise might be the best bet in May or September when children are in school. Fewer visitors often means better prices.

Consider the Ship’s Other Passengers

When planning a cruise vacation, active adults should consider their ideal environment. If retirees are traveling with grandchildren and family, a kid-friendly cruise is perfect. However, if active adults desire an upscale, adults-only atmosphere, they should explore cruise lines that better meet their expectations. Travelers who want to enjoy the journey with peers and like-minded individuals can explore age-restricted cruises, which are designed specifically for travelers age 65 and older. Another resource is CruiseCritic.com, which has passengers’ experiences with various cruise lines.

Explore Expenses

Consider what you'll be spending when hitting the shores.

It’s important when planning a cruise vacation to not overlook other expenses, such as airfare to the port and the cost of incidentals and shore excursions. Active adults should consider how much they would like to spend on the cruise vacation, and plan to add some extra money to their budget for special extras, such as a once-in-a-lifetime helicopter ride over Alaskan glaciers. Some active adults may prefer to splurge on a balcony stateroom, giving them spectacular views of the coastline and open water. Many cruises offer all-inclusive packages, giving travelers access to all-day dining and drinks, with gratuities already included.

Plan Excursions Early

Active adults should note that many popular excursions sell out quickly. It’s best to plan activities early to ensure you don’t miss out on something. Cruise ships also have a limited number of treatment rooms, so if you plan on pampering yourself with a massage or spa treatment, you should book appointments in advance.