How to stay on track on a cruise?

LOL I don't think you do! Not completely. I'd suggest picking one meal each day to be your 'indulgance' meal, that one meal is when you let yourself overeat and let yourself have some of the more decadent foods. The other two meals that day have to be much more healthy. Also, use the ship's gym or walk/jog around the deck a few times. You're on vacation, enjoy it. Cruises have amazing food and you shouldn't completely deny yourself of the experience. Just don't completely go off the rails. Or ...don't go overboard, bah dum chhhhh!

Another thing is to at least have dinner in a dining room. The portions are usually reasonable and there should be delicious, but healthy choices. Stay away from the buffets as much as possible! Also, don't worry about it, too much. Have fun!

Use the gym, walk the deck before meals, take the stairs, and indulge yourself a little, too. I've been on three cruises since joining MFP and it really hasn't set me back much. If you gain a couple of pounds you know how to get back on track.

Enjoy yourself but don't go crazy. Hit the gym up or the outside track, or do at least one active thing a day, and then forget about it. Just because all that food is there doesn't mean you have to eat it, but you can try it!

never ever take the elevator. go to the gym. do active excursions (on my alaskan cruise we did a 2 hour kayak excursion and walked into town in each port). try a little of everything on the cruise (I'm a picky eater but one day they had an alaskan food buffet with reindeer and a few other native foods. I had a bite of 2 or 3 things during the dessert extravaganza). The buffet was not all that fabulous but the sit down meals were great and were not large portions.

above all, enjoy!

Walk a LOT! Take a walking tour or two around the boat a few times a day and eat in the fancy dining room rather than any of the buffets so that you just get the one simple, portion controlled meal rather than heap on lots of junk at the "serve yourself" areas. Swim, walk, avoid too many desserts.

When it comes down to it though, screw all the advice and just have fun!

I love Royal Caribbean. I went on a 7 day RC cruise several years ago and loved every minute of it. Especially the buffet area! It's a very nice cruise line. I'm ready to go again, we've been talking about it actually.