2 things you can't do on a Royal Caribbean or Carnival cruise ship

For many people, a cruise means letting go and just being in pure vacation mode. You can eat excessively without spending an extra penny as both Royal Caribbean and Carnival offer multiple included dining options as part of your basic fare.

Drinking to excess (or at all) requires spending some extra money. You can either pay on an as-you-go basis or buy an all-you-can-drink package. For Royal Caribbean (RCL) - Get Free Report customers, that truly means "unlimited," while Carnival caps your daily consumption of alcoholic beverages at 15. 

DON'T MISS: Carnival Cruise Line responds to service cut rumors

Both cruise lines will cut you off if you're visibly intoxicated, but they will serve you as long as you're not making a spectacle of yourself. You can also smoke on Carnival and Royal Caribbean ships, albeit only in parts of the casino and in limited areas on the pool deck.

You can, of course, also gamble on Royal Caribbean and Carnival Cruise Line (CCL) - Get Free Report cruise ships from the age of 18, which is younger than at most land-based casinos in the U.S. (The drinking age, however, remains 21 on all sailings from the U.S. although in some ports it may be 18.

There's not actually much in the way of indulgence you can't partake of on a Royal Caribbean or Carnival cruise ship, but there are two things that are expressly (and surprisingly to some) forbidden.

You can't have canabbis onboard

Both cruise lines follow federal law when it comes to cannabis. Even if you're from a state where marijuana has been legalized or your cruise leaves from one, it's not legal to have it onboard.

In practice, anyone with a nose knows that some people break that rule, but the cruise lines have stepped up enforcement. Both Carnival and Royal Caribbean operate out of ports controlled by the U.S. federal government, which uses drug-sniffing dogs. Carnival has also been using drug-sniffing dogs on some sailings.

"As for the drug detection dogs, well let me say that they have, along with our no tolerance rules and enforcement, made a massive difference to the problem of people thinking it is legal and allowed to use marijuana on their cruise. It isn’t," Carnival brand ambassador John Heald posted on his Facebook page.

Getting caught with cannabis, even if you have a prescription for it, likely means getting kicked off your cruise at the next port.  

ALSO READ:

• Battle of the 'Best Fast-Food Breakfast Sandwich' Ends with a Clear Winner
• Costco Bakery Introduces 5 New Tempting Desserts
• Flight Attendants’ Gross Warning About Airplane Seats Have People Disgusted
• Woman and Family Infected With Bed Bugs at Well-Known Las Vegas Hotel

You need to wear some clothing

If you spend time on a Carnival or Royal Caribbean cruise ship, you will see all manners of bathing suits. There will be older men who have perhaps exceeded their ideal weight wearing Speedos, women in barely-there bikinis, and every style in between.

Women can wear a thong or even a g-string at either cruise line's pools. Some might argue the appropriateness of that given the children presentLas Vegas Strip faces a huge problem that could ruin major events but as long as your parts are technically covered, you are not breaking the rules.

Neither Royal Caribbean nor Carnival allows topless sunbathing. That's true in adults-only areas as well as any other part of the ship no matter how isolated you might be. 

Virgin Voyages, an adults-only cruise line, offers a topless sundeck, "The Perch," but Royal Caribbean and Carnival require minimal covering.