RELATED: 5 Things You Should Never Bring on a Cruise, Experts Warn. There are so many people working to make your experience on a cruise great, and it’s important to thank them—not just with a smile—but with a tip. Gratuity, however, can be confusing if you don’t do your research beforehand. “With respect to tipping, I would check to confirm if the cruise line hasn’t already added a gratuity to the cruise fare because some do that,” says Tim White, founder of travel site MilePro.com. In that case, you could easily square everything away before you wind down. While each line has different policies when it comes to tipping, a general rule of thumb for U.S.-based lines is about $14 to $15 per person per day, according to Cruise Critic. “This policy varies from cruise to cruise: some include the gratuity for all services while some only include it for spa staff and not dining and room staff and others have yet different policies, so the best thing here would be to ask the cruise company,” says White. Of course, if you happen to dine less, that will impact gratuity. Usually, the tips are pooled and divided by the dining and housekeeping staff. Should you be in a suite or using a butler service, gratuity might differ. But generally, if you’re extremely satisfied with the service, you can feel free to give them a little extra. Do keep in mind it’s not necessary to tip the captain, cruise director, or entertainment crew. In any case, having a baseline is always ideal. That way, undertipping is never a concern when you’re trying to thank your favorite bartender. RELATED: For more travel advice delivered straight to your inbox, sign up for our daily newsletter. According to Cruise Critic, there are some luxury cruise lines and river lines, as well as British and Australian lines, where gratuity isn’t required. But that doesn’t necessarily mean you can’t do it at your discretion. However, some crewmembers may not be able to accept gratuity, so make sure to do your research on tipping before you leave for your getaway.ae0fcc31ae342fd3a1346ebb1f342fcb Since gratuity is required on certain cruise lines, we can’t stress preparation enough. That also means making sure you have various forms of payment on hand. While certain liners will just add gratuities to your overall bill, meaning you’ll get a charge after disembarking, cash tips are often preferred as an option. According to Cruise Critic, many cruise lines ensure that passengers have envelopes so that they can give cash to the crew when they depart. It’s important to note that “river lines give passengers the option to pay by cash or credit card at the end of their trip.” RELATED: This Is the Most Dangerous Place to Be on a Cruise, Experts Say.