Go down 6 questions as this has just been asked & answered in detail.
Folding green stuff called US $.
Monopoly money...if they then have the game onboard you can sneak a few dollars out when you run out.
Dead president money will be needed . . . ie US$ LOL.
US dollars are the best.
american dollars are the ones to get.
U s dollars.
US dollars are the norm though earlier this year when paying for some goods my dollars were getting low. Went to pay with a credit card and the lady serving saw I had a good bit of sterling(pound notes) and asked us if we would like to pay in that as they got a better exchange rate. Was given a straight two dollars a pound on our purchase.
I found when I last went on Ocean Village to the Caribbean that on board you don't need anything other than English £ to exchange for local currency, but I also took $'s incase some islands will accept American $ to spend. I only exchanged small amounts for local currency as each island has different money. I did find that on bigger islands, like Barbados, St Lucia, or any that belong to U.S., like U.S.Virgin Islands, it was easier to use credit cards and $'s. Take known cards like Visa or Mastercard. Smaller islands would only accept local currency so I exchanged enough to buy small gifts. It isn't worth exchanging too much on each island as it is not possible to return unused currency on board. I am also going to the Caribbean on OV2 next March, so I will be doing the same as last time. Hope this has been of some use.