cruise

Yes.
It is mostly water weight and will come off after a few days of eating normally.

It would be a challenge. Your profile isn't viewable, but let's say your usual maintenance is 2,000 calories. When you're at sea, you might be fairly sedentary, but when you go on shore you'll be snorkeling, walking around, maybe climbing around the rainforest if you do one of those treetop adventures. So say, 4 days where you burn an extra 1,000 calories or so. That's 18,000 to maintain on the cruise, or an average of 2571 per day.

To gain 10 pounds in the course of a week, you'd have to overeat by 5,000 calories per day (3500 calories per pound X 10 =35000 divided by 7 days = 5000). So you would have to eat 7571 calories every single day, or upwards of 20% over your usual DAILY maintenance calories at every single MEAL.

Now, you might manage that on the day of the midnight buffet, but like I said, it would be a real challenge to do it every day.

I did gain 10 pounds on a cruise (and I was working out on the ship - I ran 10K one morning!). I don't think I had ever, or have since, eaten like I did on that trip (my honeymoon)..at 2am I'd go to the pizzeria for one or two slices of pizza..after a giant dinner at 9pm which included 3 or 4 desserts!

Part of it was water weight, I think 3 or 4 pounds came off right away..

It was soooooo worth it:)

I heard from a trainer on a cruise once that an average weight gain while on vacation is 1-2lbs per day, but it's mostly that all of the food is very full of sodium, so it's water weight and bloating (for the most part, at least). Basically, don't worry too much and stay hydrated

Yes, especially if the toilets stop working.

Sorry! :-)

Seriously, depending on how you decide to cruise, I could see gaining 10Lbs. if you "really take advantage" of those amazing meals that you get a cruise, and decide to just lounge on deck instead of doing excursions.