The length of a boat cruise to the Caribbean varies depending on which port you depart from, but it generally takes just a day or 2 to reach your first destination. On a Royal Caribbean cruise from Miami or a cruise to Cozumel from Port Canaveral, for example, you'll be at sea just for a day before reaching your first destination. Depending on the number of stops, however, you could easily book a 7-day cruise to the Caribbean or longer. Given its proximity to Florida, you can also find 3-night cruises to the Caribbean from Fort Lauderdale, or even a weekend cruise to the Bahamas.