We have traveled many of the cruise lines and not once has anyone said anything to us about bringing can sodas on board. The cost on some ships is very high if you get cans from the mini-fridge so we just don't do it. We always have left overs at the end of the cruise and give those to the cabin attendant all of whom have expressed their appreciation. The cruise industry makes us do this with all of the charges one has in crusing these days. Our last three cruise prices were actually less than our charges aboard the ship.