USD or local currency?

You have done your research on places that you want to visit; the next equally
important piece of research is what currency to take. If you are travelling to a
country where the official currency is not one of the major currencies then the best
thing to do is to keep USD as ‘emergency funds’ and local cash as main spending
money. To pay in local currency will be much more economical in terms of savings
since you will be able to get more value than by paying with USD. For example, a taxi
ride in St Lucia from the airport to the hotels is USD $60 or East Caribbean $150, if
you do the exchange, you will see that you are saving by paying with East Caribbean