Once on the ship and finished with the cell, it goes into the safe with the battery removed until debarkation day.
Others may spend whatever they wish to spend, knowingly or otherwise, on their cells at sea. As long as I'm not an unwilling participant in their phone conversation. If I am, I ask the cell phone user to go somewhere private to scream their conversation. They seem to realize the greater distances at sea which makes them talk louder. Or maybe its that they are infringing on my cruise vacation that makes it seem like they are talking louder.
I looked up the definition of vacation and cell phones were not a part of that definition!!