Not on purpose....
We travel quite a bit and I do find it difficult to stick 100% OP on a cruise. When I was on the beach last time, I always tried to be 90% on plan while I was gone. I'm sure I consume more calories during that time, but I also try to pick up the activity a bit.
I don't generally weigh myself until I'm home for a few days, there is so much sodium in the food and water on the ship that I know I'm retaining water. When I do weigh about 3 days later I'm usually about 3 pounds or so lower than I was when I left... I've often wondered if I'm not eating enough at home.
We're leaving in 2 weeks for a couple of weeks, so hopefully I have the same experience this time around.