May I suggest that you purchase a full set of adaptors for UK, USA , Europe and the Far East. I have found these invaluable and never leave home without them. I have not had to ask your question since buying them. Sorry I hope that didn't sound sarcastic, it wasn't meant to. .....Neil.
110 volts (cabin)+ 220 volt Shaver socket (bathroom). You will need a travel adapter as they use American 2 pin.
Were on the emerald in dec most ships have us sockets in cabin and you only need to bring the one adapter from us to uk most appliances are in the cabins what is it you are intending taking .