Taking out cash on a credit card is the worst thing to do as you are charged heavily. To see what your charges are look them up on the web or give them a call. It is much cheaper to use a debit card in an ATM which is very easy in the caribbean or madeira. You are only charged the current exchange rate and should not have a charge of min £2.50 for getting cash on your credit card. I have a Nationwide account which has no charges for use abroad on their debit or credit card. I keep this for use only abroad and put money into the account before we go. That way your main account is safe from any fraud and you always have this account to fall back on if cards on the nationwide one have to be cancelled etc.
For more travel money tips go to the free site www.moneysavingexpert.com/travel and click on the easy to follow links. This is the site I took the advice from and it was good advice !! You can often see Martin on GMTV, Breakfast and he has a show on CH5. Have a lovely holiday. (Ps. use your credit card to buy any holiday /transport/travel as it offers protection. Also check your insurance carefully).
For Madeira the euro and or credit cards, but it is handy to have some cash for smaller items. The Caribbean best use US dollars and a credit card given the rate of exchange £ against $ at the moment. You could for safety reasons take your dollars as traveller cheques which you can cash on the ship at no cost for paper dollars.