Highlighter for daily cruise activities I don't want to miss, passport (and photocopies of passport in each piece of luggage), emergency phone #'s, cc and Debit card with their phone #'s, smartphone, meds, flashlight, camera, and probably some clothes...lol.
The last thing I do is carry a lot of cash on a cruise. If I need $, I'd don't mind spending $10.00 on an ATM fee...keeps me in check spending-wise. Although I do take many $1.00 bills for tipping.
Oh, and, the phone number of my boss when I tell him I'm not coming back!