Oh right...in that case i would give p and o customer services a ring and see if they can help....if not and you just want more copies of what you already have, I think some places (??Boots) are able to take copies of your existing print.
Can't comment on P&O but know that a lot of ship's photographers don't keep photos after the passengers have disembarked, but no harm in trying. As for the suggestion by Morris, that definitely works as I've had copies made from photos before and the quality is reasonabl.
Your chances of getting further prints are slim even if the photographer can be found. All prints are destroyed after each disembarkation. Just think of the thousands of prints that would have to be stored and how would they know which ones were the ones you wanted as the ones I've looked at have no index number on the back and you can't say " when you were a pirate I was the one in the pink shirt and looked like Johnny Depp "! Do like most people scan and print them or take them to a photo shop and let them do it.....sorry ....Nei.