I went to all of the same 4 ports. Brought water (in a sport bottle) with me from the ship. only purchased bottled or canned pop or water. Didn't eat the food, except in Grand Cayman - went to KFC for a quick bite. the food was fine but I ordered a large coke - of course, it was a fountain pop with ice. I never gave it a second thought, but later that night and for the next 2 days, I was definitely feeling "wonky." had to lie down for a while that night, and could only eat a bit of cheese and fruit (the waiter was excellent - had the chef prepare something lite like that for two nights). Had stomach pains for two days, and that was the only time I felt the motion of the boat (while I was already sick). My advice would be to definitely avoid the water everywhere except the ship. in terms of food, you'd probably be ok but remeber that the vegetables and fruit are likely washed and perhaps cooked in the water. If you order room service sandwcih the morinig of a port day, you can take the sandwich with you to eat on the go. saves money too. just my thoughts.