Water Bottle Trick – The most common and the most likely to get detected! Why? Because this is everyone’s go to trick. Odds are unlikely. If you do, learn this trick:
Body Flasks, Sunscreen Flasks, Tampon Flasks, Other Custom Flasks – My personal opinion is to not keep it on your body and leave these in your luggage / carry on. Spare yourself the embarrassment. These custom methods have a high success rate, but you tend to spend more time in ingenuity. Remember, no metal, keep it plastic. And also don’t invest in something unless you can carry enough of it.
Shampoo/Listerine Bottles – Odds are you are flying to your cruise departure. If so, you now have to get screened twice. Here you are simply playing your odds at having the staff check your bottle’s.
What I recommend:
Rum Runner Flasks – For less than $15, you can order these off Amazon. They are barely detectable by X-Ray, except for the plastic lid. If you are flying and only carrying on, you can carry them empty on the plane and have your taxi stop at a store on the way to the cruise. Makes for a fun story filling them up in a back alley. Also, if you run out, at a port city, re-fill them and bring them right back through the scanner.
Bottle’s of Wine – Each person can bring in 1 bottle of wine, so you should! Class it up a little bit with some wine at dinner. Don’t go through the nonsense of imitating your wine to be liquor.
All that said, keep it classy. It’s a cruise and there are plenty of people who would really not enjoy the company of belligerence. Worst case scenario if they catch it, they will throw it out. Otherwise, they will hold on to it until your cruise is over. Or, as always, you can always claim it is your Holy Water.